Does a Staples return affect coupon?
 

I recently bought some items from Staples.com. I used a $15 off $150 coupon on the order. If I tried to return part of the order ($40 worth) and my total dropped below $150, would they give me the full $40 back or would they hold back the coupon value?

I've done that other stores and it shouldn't effect it at all.