My fnb blocked account

Fnb don't value their clients. They blocked my account in July. I went to fnb branch to find out why can't I access my account anymore since they never informed me that they are going to block my account. The consultant who was helping me told me that the reason why my account was blocked is because I recieved payment from account that was reported as **** and they are still invastigating that account. They gave me ***** department contact number and reff number *** I called almost every day but I couldn't even get hold of the person who can assist me. My question is why are didn't they contact me to hear my side of the story before they block my account. I am not happy about the whole situation I think fnb don't value their clients and treat them with fairness