Bad customer service

I purchased a jogger online, and it was small. I returned it back in store at Mvusuludzo, Thohoyandou for an exchange. I could not find the jogger I initially wanted and opted for a refund. The store told me they cannot give me back my money, but rather a voucher. I told them I want to use the money to purchase a jogger in a different store and their voucher doesn't give me that option and they still refunded through a voucher, anyway. I want my money back, either through cash or back to the original payment account. I cannot be dictated to as where should my money go. If I don't find what I want in your store, or the item is unsatisfactory, I should have the freedom of going elsewhere and not be chained to your store through vouchers. I will buy my own voucher as and when I need it.