Advice needed about a closed UC claim

Hello. My wife and I have had a joint claim for UC for about a year now. A few days ago, out of the blue, I received a message from the UC that the claim has been closed. When I checked my online account, it said that the claim had been closed due to my wife's failure to accept her work commitments. I asked her what was going on and she said that she did accept her commitments, so it didn't make any sense. I checked the notes in the journal and it said that the claim had been closed with immediate effect from 16.11.2023. Strangely, my wife had attended an appointment on the 27.11.2023 and I have had one on the 29.11.2023. We were never told anything at the times. The decision to close the claim was made on 01.12.2023, backdated 2 weeks before. Again, this doesn't make sense.
To make things clearer, there is some background information, that I think led to the closure of the claim:
-a few weeks ago, my wife went in for an appointment, only to find that her work coach had been changed, without any warning. She was surprised and upset by this, as she had a very good relationship with her old work coach, who knew her problems and has been doing a great deal of good helping her with the anxiety and depression issues she has been struggling with. It has been a very hard year for my wife, as she has lost her father a few months before and now her mother is all alone in the house, in Europe. We had just returned to London a few days before, after having had to attend to her mother's health issues.
To make matters worse, the woman chosen to be her new work coach was very rude to her from the word go. She told my wife to remove her umbrella from the table and to keep her hands off it too. I was a bit incredulous when hearing the story myself, but my wife swears that it is all true. The woman had the most obnoxious attitude she ever saw, since going into that office. She was looking down on her, with a disgusted look on her face, talking to my wife as if she was a second class citizen. She was being very unfriendly and subjected my wife to a barrage of questions like why she had gone away to Europe, where did she have the money to travel, if I am still her partner, etc. She asked for proof of travel and plane tickets. My wife uploaded the requested documents a few days later. After she did this, she also decided to make a formal complain against the way this woman had treated her and she wrote a letter in her journal, FAO one of the managers. The letter was written in the journal on the 30.11.2023. On the 01.12.2023, both her and I were sent the news about the claim having been closed. I already had an work plan agreed with my coach and an appointment date set. I am recovering from a back injury caused by a car accident and things have been getting better for me. I was lucky to have a very kind and helpful work coach, unlike my wife. Regardless, they closed my claim too, without me having done anything to justify that.
The next day, I called the online UC number and spoke to a woman who said I could ask for a mandatory reconsideration. She said I will get an answer the next day by 6PM. The deadline passed and not getting any answer, the next day me and my wife went into the office, to ask for clarification. When we eventually got to see someone, we were told that the claim was still open. The woman, who seemed new in the job was quite confused, so she asked an older colleague for help. This other woman looked and initially said the same thing, that the claim was active. However, after clicking a few more buttons, she discovered that the claim had been indeed closed, but only appeared to still be open. Hmmm. Imagine our confusion, seeing that the people in charge there could not make head or tails of the situation. I asked to see a manager. Initially, I was told there is no need for me to see one. When I insisted and asked if I was being denied the right to see one, they decided to call someone. Although he wasn't a manager, he seemed like a nice person and did his best to diffuse the situation. I asked him why my claim had been closed too, despite me having done nothing wrong and even having an appointment due in a few weeks. He said that the rules are like that and since the claim was a joint one, it is how it had to be done. I told him that it seemed wrong to me, yet he insisted that it is regulation and there is nothing that he can do about it.
I then asked about the mandatory reconsideration and I was told that it won't change anything and the best thing to do would be to just start a new claim. I asked what will happen to the existing claim, if I want to challenge the decision. I was told that if the old claim will be successful, it will be joined with this new one, but at least we won't be losing out until the matter is resolved, as it may take weeks. He asked us to sit at one of the computers and assisted us in starting a new claim.
Despite the person being nice, I became a bit suspicious of his insistence on starting a new claim. I looked online for help but could not find any information regarding having 2 UC concurrent claims. To me, it would be wrong to have a new claim, if one wanted to challenge the old one, so today I decided to close the new claims for both myself and my wife.
I have just come across your forum and decided to ask for help here. My plan is to call the UC people again tomorrow and ask why I was never given an answer regarding the mandatory reconsideration. Then go on to appeal.
I would appreciate your help in the matter. Many thanks.