Blocked bank account

I am very disappointed with Capitec after i have been using it for so long today they decide to block my account without calling me first. I have joined investment knowing it legit as the owner said he is playing Hollywood and now my account is blocked with all my funds in it. Apparently the guy was a ******* and it happened that he transferred R200 on my account as a bonus now my account is blocked because of that. I am very stressed and frustrated because this account i use it for my salary now i don't know what to do.

I went to the branch and they said they need an affidavit from Gift Tshabalala who happen to be a *******, now my question is how do i get an affidavit from someone i don't even know and has also ****med me? I need help.