Money taken out of my account without my concent

I made a booking and it gave a system error after i made the payment. After that i received confirmation of another booking ref no. I phoned in and told them and i was told they will sort it out. Only to note on my bank statement 2 weeks later that they took the money out of my account twice. Had i not phoned in i would not have got my money back. To me that is theft!!! Now i have to wait 7 to 21 working days for MY money that was taken out of MY account without my concent. To me this just does not sound fair. Am i getting the bank charges as well as interest on my money for that time paid back to me as well??? Not a happy client!!!