Hmm. As I understand it, training organisations don't tell the CAA of exam results until the initial application for a licence - so you will have to try and get the results from the school, or retake the exams.
The first thing to do is perhaps to email them the dates when you took the exams - can you find details of the payments? It would be interesting to know what records they have kept - you will need them for verification of your flying training in any case.
Can you remember who your FI was? I wonder whether (s)he may have some record?
The comment "I wouldn't do it cause it was their responsibility to manage the records" is I hope a throw away one. Without exams there is no PPL. It would be a shame to throw all your training away for the cost of resitting a few exams.
If they can't recover the records I can't really see an alternative to resitting the missing papers which is complex in a couple of ways. I think you only have 18 months from sitting the first to the last exam and you're going to be up against the wall on that.
The second minor complexity is that you are in the transition period between the old 7-exam and the current 9-exam environment and you may have to take a larger number of exams than the number that are missing. There is also the small issue of the number of sittings - but any competent training organisation will know how to handle these things.
Good luck!