In the first week of July, a beer and wine

In the first week of July, a beer and wine store sold 871 cases of beer and paid refunds on 637 cases of empty bottles, for a net revenue of $12,632.10. For the following week the net revenue was $13,331.70 from the sale of 932 cases and the return of 805 cases of empties. What refund did the store pay per case of empty bottles?