Paid twice for same goods and no refund.

I paid for goods on 10 April 2015 with a gift card from Gateway Theatre of Shopping. The payment went through but did not clear on the store's system. I then paid for the goods with another card as the store told me they would assist with a refund to the initial card. The financial service provider has confirmed that the store did receive payment for the goods. Mr Price Sport has not as yet paid back the money that they have received and if is 30 April. They are blaming the financial service provider and are saying that they must reverse the card. Since I have paid the store I hold them responsible. I have been in store now for approximately one hour. For the third time.