Poor service

On the 9th of February I was at Edgar’s in Gateway shopping centre and im not happy with the service we received.I used my payjustnow which we were told it declined but they took money on my side, and said it will reverse automatically but it hasn’t.when I enquired with payjustnow they said the merchant is the one who needs to request the refund on behalf of the customer but they haven’t been of help I need my money back ASAP.