esa- support group

hi,
i just received a letter from the dwp stating they were backdating £59.00 to my account. i decided to call them to find what this payment was for and they said it was backdated to 12/01 - 24/03.
i asked why and he said its because ive been put into the support group from the wrag. i hadn't heard anything prior to this. i was appealing the decision being put in the wrag but didnt know my payments would or had changed. he said i,m now back on £91.40 a week.
i asked him when had i been put in the support group and he said 27jan but they,ve only just done it now.
i,m to terrified to believe him incase he,s got it wrong, should i receive a letter or something confirming i,m now in the suport group as i,m meant to be doing the pathways course.