Capitec closed my account without proper investigation

Capitec bank closed my account permanently without proper investigation. I opened my account and I even told the consultant who was helping me at the branch that I sell digital products so different people will be depositing money into my account often. On 11 July 2019 I had a customer who bought bitcoins from me and he transferred R15000 into my capitec account. I told the customer before he paid that I didn't have enough coins in my account and he said that he didn't mind to pay first and then I can get more bitcoins with the money he will send to me which is why I used the money almost immediately after it came into my account to buy more coins to send to customer. I didn't transfer the money to another account, I used it to buy coins and sent them to the customer. I have full proof showing where the money went after it was received into my account and the times of the transactions backup my statement. I never knew that the customer was paying me with money that was ****** from someone else's account, how on earth would I have known that my customer was a *********? He even sent me proof of payment after making the payment into my account. I did not benefit from the money at all cause the coins I bought with the money were sent to the customer and I have proof. I have all the proof with me. The receipt showing the transaction in question and conversations between me and the buyer and I have sent all of those to capitec but they still decided to close my account. Is it fair? I'm also a victim here and proper investigation was not conducted. I am very very disappointed, Capitec has treated me like a ******** and it's not fair. Their forensic department can't be contacted, and they never contacted me to ask me questions. They just got my documentation and a few working hours later I received a call to tell me that they can't and will never unblock my account, without telling me why and how they got to that decision. I was not contacted by forensic department but a consultant at the branch who emailed my documentation to forensic department. I'm so disappointed and I need answers and clarification. I feel sorry for those who are considering to open accounts with Capitec bank. I've had such a bad experience that I regret ever having an account with them. Another bank would have handled my case differently