Extremely unprofessional and very bad service received after I've paid for an item

I've purchased a pair of shoes on Monday the 28th of August 2017 and paid with my Visa Card. After the purchase I've received a sms confirming that the purchase was successful. The branch management then said that the purchase was decline on their internal system. I then went to the bank and pulled a statement to show them that the purchase did go off my account. They said that the transaction will 'automatically' be reversed within 10 to 15 minutes. It is now Thursday 31 August 2017 and after phoning PEP customer service several times, promising me that they will get back to me, the purchase has still not been reversed. Customer service is very rude over the phone and keeps on interrupting me while I try to explain the situation. Bottom Line - Rude and very unprofessional service received while I have lawfully paid for an item which they refuse to give to me. I have done nothing wrong and now I am being treated this way... I please want my money back, this is really absurd... They also refuse to give me the regional manager's contact details. They have also promised that he/ she will give me feedback which they never did. How can this be lawful, paying for something which you never received? This is by far the worst experience I've ever received. What now? What is my rights as consumer?