Hi Shelly -- It sounds like you should file a warranty claim, most likely through the retailer from whom you purchased the mattress.

Medallion Mattress Company doesn't appear to have a website, so its somewhat doubtful that they have a way for you to file a warranty claim with them directly, however you should check the documentation you were given when you purchased the mattress to verify the appropriate process for filing a waranty claim.

Hi, Shelly...in general, for warranty, a mattress must show a 1 1/2" to 1 3/4" measurable indentation after you've been out of the bed for a few hours.
If your bed shows a lot less than that, warranty coverage is not likely. Medalllion may have other parameters, but these are very typical. To make a slightly "sinking" mattress recover a bit, I've found that if you flip the mattress over to the base side and let it sit for a few days, it tends to help the fibers recover more of the original comfort. Do this when you go out of town for a few days, or anytime if you have another bed to sleep on. I actually recommend doing this to all one-sided mattresses when you go out of town...it adds longevity to the bed and keeps it feeling new longer! I recommend this to customers when they purchase a new bed from us. Sure, I want repeat business, but not before it's necessary!!