I've actually found Home Depot to be very accommodating.
They gave us a rebate on a toilet a month ago that expired last November when it was on sale.
We've had no issues returning items and getting credit or cash back even without receipts.
We've found alot of really good stuff there even if it wasn't in the store (i.e. their online site carries alot more stock than the stores do, WAYYY more lighting options for example).

"Those who preach the myths of audio are ignorant of truth."