Blocked account, no one is willing to help

FNB blocked my bank account last year because someone sent me *****ulent funds. I don’t know where they got the money from because it was just a mere stranger that i sold my phone to. I have been trying to get hold of someone to help me deal with this matter but every time i call, they tell me that the investigator of the case will reach out to me. I have been trying to get hold of the investigator but she’s not replying to any of my emails and my account is till blocked. I really need my account back and i need to use my money in that account. This is the worst experience ever. I’m very disappointed with FNB… will i ever get help??!