Very not happy with how they handle customers

I called Jet last week regarding the account that I closed about 2 years back, the account is payed up but still reflects under my credit check as open. I went to the store to close the account but seemingly it is still open. Last week I requested for the payed up letter, I was promised that I will receive it the same day or the following day but I never received it. The problem now is that when I call they hang up my calls..