Harvey Nichols PPI via CPP

My wife was sold PPI by Harvey Nichols in 1998 and was paying it for years. She was advised in store to tick a box, and said the PPI was supplied by CPP.

She was a student at the time and her parents paid her fees and living, so PPI was useless.

I'm trying to track down who is responsible and how I can claim against them? CPP seem to have disappeared and I can't find any way to claim directly to Harvey Nichols.