what happens if he asked about a change in terms 2 years ago and was told to wait. Surely he can expect more if his work has increased such that his hours are increased?

hello all I wonder if anyone can help me. I took out a loan with Blackhorse in 2002 and it had PPI on it. I was in fulltime employment and had no need for PPi, but was told it was needed. with this being the first loan I had ever taken out, I didn't know any better. I tried to make a mis-sold PPi claim. problem is, I don't have any paperwork with account details. my own bank - HSBC - tell me they cannot go back to 2004 when I finished paying for the loan to help me get the account details. Black horse cannot find me on their system, and therefore reject my claim. I approached FOS who came back to say that Blackhorse had sent screen shots of their attempts to find me on their system, and they were satisfied Blackhorse had done all they could. My question to the more experienced folk on here is: is there any more I can do to make a claim, or do I just accept defeat hear. BTW: the loan was £6k repaid over 18 months. so I'm not even sure how much PPi I paid and if it would be worth chasing. thanks in advance for any help