Account closure

My experience with jet is horrible. I swear My problem with this store will drive me to depression. So here is my story;

I opened an account with jet over 8 years ago. Two years ago I realized that paying my account was as good as throwing my money in the river because my account balance remained the same, I asked for a statement and that's where I realized I was still being charge for a simcard contract I canceled years ago. I over paid jet money over R3000. I called jet to complain about this and the money was reimbursed in my account leaving me with a 00 balance.

I tjen continued using the account. Four months ago I realized that I was still being charged for the same simcard that caused the problem previously. I call jet to reimburse again and this time they refused. They gave me the phone number of a manager (Tebogo) this guy was rude and he told me I was making noise and they will not reimburse me as the simcard was signed for by me and left the store. I explained to him that the simcard was later canceled and that's why I was reimbursed the previous time. The guy was just rude and he told me it will never happen, I must just pay the money otherwise it's my name that will have a bad credit record and not his. Stressed about this I had no longer energy to fight this I decided to pay up the account and close it. After paying the full amount to the last cent I requested jet store in Limpopo mall to close the account and the lady gave me phone numbers I must call to close this account. I called and I was given a new number to call from there I was sent from pillar to post wasting airtime of almost R400 until I spoke to a lady who told me to wait for 35 days before they can close my account. After the 35 days I called and it's either they hang up onecafter hearing why I'm calling or they lie about the manager who is busy writing the letter and I will receive it within 15 minutes. This has been happening for days now and I'm emotionally drained as I don't owe this people anything and I don't want anything to do with jet anymore. Please help me I'm loosing my mind over this