***** and disputes

In May I made a transaction from FNB to standard bank and I did not clear it, I tried to reverse it seeing that the company I was buying from was *****. It got reversed but was short by R10000 I asked the ***** department and I was told that I need to open another case, mind you I had to pay the loan that was short by R10000 and I lost around R20000 to fnb of which I will never get it back even though I have an sms proof that all the money was confirmed to be available from standard bank and they stopped that account. I am currently faced with debits in June it was R10000 and now this month it's +R29000, I don't understand the security system at fnb. I've been their clients for maybe in 2 years I'll be 20 years banking with them but I'm very disappointed with their treatment and service lately. I need an advice for a better bank, I can't be stressed every 26th day of the month making calls to their dispute department.