Disputed vendor transaction and FNB allows them to take more money!

I entered into a transation on 5 Sept with a vendor ...By 21 September he had not delivered and I logged a dispute with FNB to reverse the transaction. I needed to fill in a dispute form which I did and had various reference numbers. The vendor only has n online contact us ( no email address of phone number). I contacted them on various occassions to see what was going on but received no response back I to date have still not received servce service . FNB decided as I cannot provethat I speak to these people they would not reverse the transaction even though I have still not received service! As though theat was not bad enough they last night again let the vendor debot off my account EVEN THOUGH I HAVE A DISPUTE DUE TO NON DELIVEY. The service desk lady this morning did very liuttle to help -she sent me a dispute for to "try again" DisgustingFNB