Bad Service

About two months ago my husband purchased a Bed from Lewis Stores Athlone. He paid cash and the bed was delivered same day. The problem is that he requested a Firm mattress and was advised to purchase a certain Sealy bed and that it was firm. However when the bed arrived we realized it wasn't a firm mattress at all. we immediately called the store and told them that this wasn't what we want and that we would like to exchange it for another bed. they sent my husband to The Sealy supplier to find a bed. They however didn't have what we were looking for. We requested that they collected the bed that we have and asked for a refund so we could purchase a bed some where else. It has been a battle firstly trying to speak to someone from the store and to get a refund which they refuse to do unless they collect the bed. So we have agreed for them to collect, but have been told that refund will take 21 days or more. How is this possible when he paid cash? Also everyday they have told us they collecting the bed but they just never show up? Today they are apparently collecting and we have sent the necessary documents for the refund. but still now they have excuses like they don't have a vehicle to do the collection etc etc... One excuse after the next. we didn't buy on terms. we paid cash on the same day. why are we made to suffer for their incompetence?