Red Roof Inn

Book a 2 night stay at Red Roof inn on March 31 to April 2. I checked in and checked out 20 minutes later. The room was filthy. The bedspread had stains and burn holes. I could not stay there. Went I left the room card with the person at the front desk they said no issue to check out. I am being charged for the stay and the Red Roof Inn will not refund my money. I have talked to several people including Customer support service with Red Roof Inn. The hotel was disgusting and if they can not issue a full credit why can they not issue partial?