Blocked account for no apparent reason

Discovery Bank no longer values their customers they blocked my account at FNB's request. How can FNB call you and tell you I recieved money from a person who uses FNB and the person reported the funds yet the person doesn't even know about this? Did FNB give evidence of this? You just listen to them and block my account and don't even care if it's the truth or not. I called yesterday I was told to go to FNB and resolve the matter there with the person who sent me money. The person knows nothing about this and FNB doesn't even know why whoever called DISCOVERY BANK called to block my account. I'm so disappointed at how Discovery Bank is now treating customers I'm now scared of using this bank in future because anytime after receiving money for anything you could be restricted from using your own money