Problems with Proving Residency Status ( Non-EU resident )

In my student loan application, Student Finance asked me to send original documents to prove my residency status for the last three years. The Home Office only granted me an indefinite leave-to-remain visa on 18/05/23 after living for five years as an ordinary resident. I sent my permanent residence BRP and passport with a visa vignette showing my first entry to the UK as a resident in 2018. However, Student Finance told me after two weeks that I only sent evidence of residency from 18/05/2023, and they wanted my immigration status from 01/09/2020. At this point, I don't know how to proceed because I do not have any more documents I can send ( all my old BRP has been returned to The Home Office because it is a requirement to receive a new one ). Student Finance said they also accept official Home Office documents. However, The Home Office has never issued or sent me any original letters proving my residency status. Is there a way to obtain Original Home Office letters, and can Student Finance receive the original letters directly from Home Office? Or can I send non-immigration documents to prove my residency status?