Apollo Pharmacy — Refunding of amount regarding

I have bought medicines few days before in apollo pharmacy. They staff members swiped the card, after a while they said the swiping machine not working properly and made me to wait few minutes since i have entered my pin number too. Then they asked me to pay as cash and assured me the amount from my bank account won't be debitted. I payed them as cash and soon after i returned home 2 hours later there was a sms regarding the transaction details and the amount debitted from my account... So i have paid in double for them... I have asked them and told them to check it out but they put me in trouble by making me to go to my bank for confirmation regarding debiting... I showed them the invoice id and transaction id even though they are passing their time and not checking for me by excusing me that that have to call the head office for refund... But the transaction details is already given to them... They are soo irresponsive... Even after calling they are attending and keeping the receiver aside... With no response...