After Purchase return the amount is not credited back to account from which amount is debited while purchasing

ERPNext Buying
1

while purchasing items worth 1000rs amount is debited from buyer account A and credited to seller account B.
After some time buyer want to return some items worth 500rs.
For purchase return i clicked option purchase return from purchase receipt.
after completing the cycle in account ledger amount is not credited to buyer account and not debited from seller account

2

Do the purchase return against the Invoice too.