Paid up letter

this a bunch of most *********** people i have ever seen,i paid up my account with TFG in january 2020,i asked for a paid up letter,they requested i give them 7 days from the day i requested it,now its been 7 months waiting,i call their call centre everyday,they tell me they will send it if they dont hung up their phones on me i have been sending emails almost every month from january 2020,they just give me excuses that its been lock down and i requested the paid up letter way before the lockdown,what makes me so angry is that today i requested to speak to the call Centre manager but she is not willing to help me she said there nothing they can do on their side, she just gave me the same email address to send them an email again, in which i have been sending them emails since january.i dont know what to do anymore all i want is my paid up letter thats all.