Money siphoned from credit card AGAIN!

I have just about heard it with FNB. I have experienced this several times where u find money missing from my credit card which is not traceable. I have a credit limit of R10000 which I keep at that level. Several times I noticed funds missing from this account but nothing was purchased and it doesn't show on statement history and the bank is unable to trace it. The only way the bank can help you is, if there was a transaction. In this case, and several which I reported, the bank has been deaf to my complaints. This morning, I woke up and R120 is missing from my credit card. No line item of what the money purchased. I haven't used the card in the last 48 hours. Someone who has access to my account is definitely siphoning this money and I must be liable for it because the bank can't account for it and refuses to listen to its loyal customers and investigate the matters. This is extremely frustrating. This is definitely an inside job.