Purchase made May, keeps being debited to my c/c

I made a purchase from Sheet Street in Killarney Mall on May 2nd,. 2015. At the time of the sale, the sales lady professed that the entry was not finalised on their system which means I didn't pay for the goods. I received a confirmation sms though. They goods were withheld and I left empty handed. Once I received my credit card statement I confirmed the payment had in fact been made and contacted Sheet Street Killarney. They were helpful at first, but requested I fax them my statements and info as proof. Their telephone line is the same as the fax and after a lot of attempts we couldn't get the fax through. They queried it with their bank who couldn't \find"the deposit on their side"