G. Other
He didn't lose anything.

The riddle never specifies that he refunded shop A his 1000rs, and given the situation there is no reason for him to have done so.  Given the lack of supervision by shopkeeper B on the 1000rs bill while in the possession of shopkeeper A, there is nothing that would suggest the bill is the same one the lady bought goods with.

As the goods sold were at no profit, the total change in revenue is 0.