MISSING UNPLANNED INTERVENTION PACKS

At the moment I get PIP Daily Living at the standard rate which was awarded in October 2014 after waiting 29 weeks for my medical assessment under ATOS.
Just days before completing and returning my PIP claim form I had a very bad fall and I only mentioned the fall as the last appointment I had with my GP.
Since the fall my health and mobility declined to the extent that I was referred to a spinal specialist and a cardiologist. I took the extra medical reports with me to my assessment but none of them were included in the report.
As a result of my fall I have 2 bulging discs at the base of my spine which have damaged the nerves for my left leg and now need either crutches or a 4 wheeled walker to be able to walk.
On 5th March this year I phoned DWP to inform them of my worsening medical condition, and was informed that an "Unplanned Intervention" pack would be sent out for me to complete. I phoned again on 25th March, the 21st April and the 18th May. Each time I called I would explain why I was reporting a change of condition and each time I was promised that a pack would be sent out, in fact the lady who took my call on 18th May flagged up my request as an official complaint which had to be actioned within 10 working days!
Finally on 15th June - 14 weeks after I contacted them - the DWP phoned me at home to ask if I still wanted to continue with reporting my change of condition as I will have to have a complete re-appraisal of my claim and might have my existing PIP award taken away. But at least the forms were on their way to me – NOT!
On 8th July I received a letter to remind me that I had to return my PIP forms before 15th July. So I phoned DWP to inform them that I was still waiting for the forms and was assured that a second pack would be posted out to me.
I phoned DWP again on 17th July to ask about forms and was informed that a second set of forms had been posted out on 09th July. On the 22nd July I called to report that I was still waiting for the forms to arrive and was asked to give them a few more days to arrive.
It is now 29th July and 22 weeks since my first phone call to report the change to my medical condition – and still no forms. I have phoned DWP again this morning and a very helpful lady said that she would progress my case and get it issued to a case manager who would then have to phone me back within 1 to 5 working days (but give it longer because the case managers have a back log). And suggested that I raise a complaint with the Post Office for my missing mail.
Vent over – can anybody suggest a way that I can get my hands on an "Unplanned Intervention" pack? Any information or suggestions gratefully received.