Unauthorised transactions

We received a voucher for R4000 for a flight to anywhere in South Africa. We attempted to book the flights which had a full price of about R6500. The result would be that we would only be charged R2500. We were told we could only make credit card payments over the phone so I gave my credit card details. I was then told it was declining for an unknown reason so I gave the details of my husbands card. The transaction went through and we were issued with the tickets. A few moments later I received an sms to say that the full R6500 had been put through on my credit card as well. I attempted to contact them to resolve it and they spent 3 days trying to "locate" these transactions despite me having sent proof. They then informed me that they couldn't find the transaction and that I would need to take this up with my bank. After being told this I went into our account and found that not only had the R2500 been put through but so had ANOTHER R6500 on my husband's credit card. We keep this card for emergencies and so the limit is very low and now the account is overdrawn and he is receiving calls from the bank requesting immediate payment. We have attempted to contact the manager and she is always in meetings or unavailable. DO NOT TRUST THIS COMPANY WITH CREDIT CARD DETAILS. it has still not been resolved. When I called one of the agents, she spoke as if she was doing me a favour by trying to sort this out despite the fact that this should not have happened in the first place and was offended by the fact that I was angry. She maintained that she was not there on the day it happened - to which our response is she is the face of the company - who else should I expect to talk to?????? SORT THIS OUT !