Great news JaySay
I got my PPI payments back on two cards I had about ten years ago, no trouble at all just wrote to the bank as per letter templates online, and got it paid into my current account. It wasn't a lot of £, about £100 altogether as I recall.
However I also put in a claim for my partner and they protested, implying that it wasn't mis-sold. I replied to that letter and they have failed to respond as yet. I am glad you reminded me-I am going to chase it up today.