Cellc worst company ever!

My Contract expired in January 2020 was never terminated because i was suppose to notify them. fine i did notification to terminate which ran until February 2020 and my last payment was in March 2020. Now I app**** for finance with the Bank and the credit bureau said I am owing Cellc which I did not. I then phone Cellc who rep**** by saying i don't owe them, I then requested a paid up letter *** and was told it takes 48 hours this was on the 29 May 2020 but up until i do not have this letter everytime i do a follow they LEGAL is busy with this and my life is standing still because the bank wants the letter and Cellc is not giving me this letter. This is the worst company I ever dealt with and will never advice anyone to deal with them.