Pip backpay confusion change of circumstance

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 had written on all of my forms/diaries etc that conditions worsened in April/may and September.

I haven’t received letter yet, 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. I 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, so a separate letter. This doesn’t sound normal? As I was told my backpay entitlement is 124 on the phone and coming in on the 23rd.

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