Payflex not paying me a full refund

Payflex is a reap off.. I want refund I have a query I bought items worth 3351 I have already paid 2234 Im due for a refund worth 1636 for items I returned.. Original order 3351 Returned items 1636 New order amount for items received 1715 Already paid 2234 overpaid 521 Refund still due is 1636 Total owed to me 2155 I only got a refund of 521 Please refund me the rest of my cash.. RESPOND to my quiry.. I need the money to reorder the items ..