blocked account

Fnb bank service is very very poor. My account is blocked without my permission to do so and its not fair ive received an email on the 14th. I immediatly reply to that email to chief with proof, i called him 1000 times i cant get hold of him, his name is Ondela (the chief). iam so dissapointed in their service cause iam a mother of 3 children i worked for them every single day and my salary gets paid into my account. I sold a chair to someone on marketplace i dont have a clue where his from he paid money into my savings account for the chair but he came when i was not home so he reported me to fnb bank, but the following day he came and collect the chair but he didnt told me about it. Now he is gone my account is on hold and they told me they dont have his details also, only that shocked me. please i need advice please its urgent