Hi mnguy,
I don’t keep a record of the or return/exchange policies of the manufacturers or retailers on the various lists in the forum and I don’t know them off the top of my head but their websites or a quick phone call to the sources on the Minneapolis list should give you the information you need.
The only retailer or manufacturer on the Minneapolis list that has a refund policy as far as I know is Room & Board which has a 30 day refund policy on their mattresses (with no charges) but I would make sure you check the density of the memory foam in their mattresses because they may be lower than the 4 lb guideline I would suggest.
Phoenix