You should not even have to ask for a new mattress...if the dealer does not automatically give you a new mattress without asking I would question my choice of dealers...
From Central Texas
2014 Cedar Creek Silverback 29IK
2010 Dodge Laramie 3500 Dually
My Steelpony....2007 HD Ultra Classic...done up in a memorial to the 343 firefighters who died 9/11
Never Ever Forget....yes I was a Volunteer FF for 20 years........