Bad service

I had a contract with cell c which I terminated in December 2018 and phoned in January to check if I had any outstanding payment and I was told that I did not have any. I have been calling them since 02/03 requesting a paid up letter and I’ve been transferred from one department to the other, on the 13th I received an email with no attachment and call them back on the 14th and was told that I would receive the letter before 12 I am on the phone still being transferred and told to wait for longer. I have never experienced worse customer service