FNB makes money disappear

Made deposits to my account. Received confirmation message. Today, 3 days later the money that was paid in and available is not there anymore. Not even showing the deposit on my transaction history. As if it never existed. Tried secure chat. No response. Phoned (after the idiot robot can't understand me) eventually got through just to be cut off. Pathetic. FNB is very fast becoming the worst bank in Africa!