Bad customer service from TFG

I normally pay my account on the 28th of every month even though the contract states I have to pay on the 1st. It so happened that I paid my account on the 1st and I was told that it’s a late payment and was charged for it. Then I missed one month’s installment. Thereafter, I settled the remaining balance and my account was blocked. Now I’m charged for having a active account whilst I can’t use it because it’s blocked. The store advised me to email the head office of which I did but up until now I haven’t heard any response. I want to close this account because it’s of no use to me. TFG is the pits really. I have tried to contact them through the store but continuously put on hold. Now I’m paying interests I shouldn’t be paying in the first place. I’ve always experienced such bad service with TFG, opening the account, keeping it active and trying to close it.