No Communication and recharge

I disputed a charge on 15 January 2015 which was reversed on 15 March 2015. The dispute was relating to a second charge from a merchant I did a transaction with. I authorised the one , but not the other. On 24 April I was charged again and contacted the merchant via e-mail to refund me. The merchant then referred me to the bank for a refund as they did not charge me again. So I call the bank and I am told they recharged me as there is proof of me giving my details to this merchant. Obviously I did, because I did a purchase with them which I later cancelled due to this second charge being made. So now I am made to understand I cannot get my money back. And how come when the bank received documents from the merchant was I not called to inform me? Why just go and charge my account again? I am done with FNB. I've said it a few times, but this time I am completely done. Please advise how to close a 32 day investment account as I will be closing my cheque account, savings account as well as my 32 day account. Customer satisfaction is clearly not one of FNB's priorities as the lack of communication is sickening.