Double charge for goods

Sunday morning just before 10 I went to Jet in Bayside to buy a few things, so as normal the goods were scan and then I signed for it but when they wanted to print there was something wrong with the printer and they told me the transaction is not seen on my account so they must do the whole transaction over again. The first amount I have signed for was R590 something which they said to me didn't go off. So they started the transaction over again by scanning everything again, because I believed them that there were something wrong with the system. So I signed again for the same goods but this time the amount was R841.90. So yesterday I recieved my statement and see that suddenly the balance on the slip and on the statement don't compare at all so I worked it out and see that the R590 was also added to my account. Please fix this asap Please remove the first transaction as I am not going to pay it because it was doubled captured.