Worst service ever

Settled my bill asked for paid up letter was told to wait 21 working days I did went to get it was then told 5working days for it to be sent, I called after 5 working days was again told 48hours called after that was told we can see it’s settled but it’s been blocked we can’t send it, was given email address to complain and to query why it’s blocked, service is atrocious I curse the day I opened the account