Claims from the 90s - no paperwork

I definitely had loans, probably with PPI, in the early 90s. I have no paperwork, no records of the agreement number etc, I only have my bank statements saying I paid the HP company. My bank have been hepful but cannot find the agreement number or other related paperwork. Santander have taken over the HP Company and say they cannot help me without a reference or proof of an agreement with the company (bank statements only prove I paid XX every month).


How or where can I find info regarding my loan/HP agreements from the 90s?


Any advice greatfully received.