The amount of the refund owed to the customer is $41,064.
Here's how to calculate it:
The net amount due on the sale is $43,600 - (2% x $43,600) = $42,728.
When the customer returns the entire shipment, the seller owes a refund of the purchase price minus the cost of the merchandise returned.
The purchase price is $42,728, so the refund owed is $42,728 - $26,160 = $16,568.
However, since the customer paid $43,600, the refund is limited to that amount. Therefore, the refund owed to the customer is $41,064 ($43,600 - $2,536).