Thanks for the replies. In the end, I also contact Citizens Advice & received the following: "I understand that you have received a Notice of Assignment from Hoist Finance and that you no longer want to receive letters from them as the original debt was paid off in full last year. If this is the case, then you should provide proof that the debt is paid to Hoist and ask them to cease any further recovery of the debt. If they do not stop contacting you, then you should contact MBNA and ask them to inform Hoist that no debt is owed and therefore cease any further contact." My approach, since I do not want to deal with Hoist directly, will be to make a Data Subject Access Request to MBNA (as advised here by Andyorch) so I have the info demonstrating that there is no balance and the account is closed. Then I will contact MBNA to ask them to deal with Hoist (as advised by Citizens Advice).

Hi, I've received a Notice of Assignment letter from Hoist Finance UK Holdings 1 Limited. It relates to an MBNA credit card debt that I paid off in full October 2017. There were no late payments for the duration of time I had the debt, and the balance they have on the letter looks to be from many years ago. I've seen from other posts here that you can send the holding company a request for more information and what data they hold on you, but since I don't owe any money and they currently have extremely out-of-date information about me (only address is correct), I don't really want this to become a dialogue. My question is: how can I make sure I don't get any more of these letters? Also, if I can, I want to be able to take further action - it is amazing to me that debt buyers can chase old data in the hopes they can get grab money of people that either don't know that it is out-of-date (not everyone is a credit report nerd) or that they no longer are legally required to pay. I found it a little scary to receive the letter, and that's with full knowledge that it is trash. You know when something is legal, but horribly wrong?!