Wrong amount refunded

I've bought 2 items from my run away and 1 item was returned so my run away refunded that 1 so before they can I paid the balance on my payflex app so they took the refund that was paid by my run away to pay the remaining balance on the app and refunded the balance so now my problem is that paid the balance in full they have to pay back the refund paid by my way back in yo my wallet. I've been calling no luck sending emails no response ,even their what's app no help.Payflex is the best but when it comes to refund it's a roller coster they miscalculate