Deducting output VAT of Sales Returns

We have been deducting Out put VAT on Sales Retunrs.

By passing following entries

When Sale is made

Party a/c Dr

To Sales a/c

To Out put VAT a/c

When Sales returns

Output VAT a/c Dr

Sales Returns a/c Dr

To Party a/c

Now department people are telling that VAT should not be deducted on sales return

Pls advice me