Pip backpay change of circumstances

pgeex

hi bit of a weird question

I was receiving standard mobility but my condition worsened drastically. It worsened in around April/may 2024 and then again in September 2024. I submitted change of circumstances call on the 8th October and was sent forms etc. then I had my assessment in December and decision 20 Jan for enhanced for both.

I haven’t received letter but called up about back pay as online calculator shows around 2245.03 in backpay from 8th oct - 18 Jan but pip on the phone said I’m only getting 124 backpay due to some being sent to debt management. Contacted debt management they said 1200 is owed but due to needing the money they are doing a payment plan for me. But there’s still around 1k missing from backpay owed?

Called pip and they said that I should get a letter explaining but the 124 is money owed from 31st - 7th January and to wait for a letter regarding backpay.

Surely there’s a lot of money missing somewhere, is it usual for them to send separate letters for backpay?