Travelocity Double Charged for Flight Change Worldwide Internet

I booked a trip through travelocity over the phone , that was mistake #1...from Ontario California to Nassau Bahamas for $2871.

When I got the Itenerary I realized that on my return flight I had an almost 12 hour layover....So I called Travelocity 

back and changed the flight , When I called the man seemed very helpful and changed the flight , When I asked about the fees he said it would be another $243 , which was ok as I chalked it up to me not paying close enough attention, the he said " do you authorize for me to take $243. out of your account to which I said yes ....so I think everything is A ok...Wrong  !

I checked something in my Bank Account and there was a pending charge for $486.. I called Travelocity and spoke to a Rep who passed me over to Supervisor named Jan who told me that the $243. was per person, I told her thats not what the rep said, she asked about a receipt for that transaction but I never got one ....I feel stuck right now , Im thinking of calling my bank and stopping payment.....Any Ideas or help would be appreciated....