I was naive until last year when I learnt from your excellent site about the antics of DCA's. Until then, about July 2021, alas, I was paying Shoosmiths £5.00 per month on this, along side three other debts with Nat West, a Bank personal loan and two personal guarantees on Business borrowing where the business defaulted. I still don't know what to do about these latter debts.
I then received a letter from Equivo saying they had taken over the management of the debt from Shoosmiths and noticed that the Credit Card number was one of which I had no record so fired off the S78 letter to them and stopped paying. As you say no letter of claim!
Now I have received the letter from RBS it at least clarifies that the debt is still with the original creditor.