Cell C is useless

I am very angry at how cell c is treating me after being with them for many years, I have been trying soo hard after paying my last installment to get you to please sent me a paid up letter and update my record as such on all credit bureaus. You have given me nothing and I am tired of calling your call centre even visited the store to resolve this, no luck at all, you are indeed making it easier for customers to leave due to lack of custor service