I am using the perpetual inventory method.

I purchased 500 units at 5/unit.

Inventory........................... 2500

accounts payable..... 2500

I sold 300 units at 9/unit.

A/R.................................2,700

Sales.......................... 2,700

Cogs............................... 1,500

Inventory............................... 1,500

The customer returned 50 units. How do I record the journal entry for the customers return?