FNB Credit card refund

I made a purchase at a store with my Apple Watch on the 15th of March. On the 16th I returned the item, but the salesperson refused to credit my Apple Watch and put the refund on my physical credit card. I have not received my money back and the store says the money was taken from their account. When I phone FNB they say the store must contact them and when the store contacts FNB they say I must contact FNB. I don't know what to do and how to get my money back. Very disappointed. 😞