Sleep Country Canada

We bought a twin mattress with 10 years of warranty for our child in 2010. Now it is crashed in the middle, so we contacted its warranty service department. They asked us to take and upload many pictures of the mattress. We did everything they asked for, and we also stated there are some stains, but we don't care. The only thing we need is to fix the crash. Now, they sent us a letter, said we must get it professionally cleaned. How much would be for the professional clean? $100, $200? We don't know. We don't know it will be satisfied either after a professional clean.
The interesting thing is that Sleep Country won't take and won't need the mattress back because it has been crashed already, no matter whether or not we clean the mattress. Actually a sales gentleman in the store told us that Sleep Country won't have it back as it is used and defective. So, basically Sleep Country tries not to honor the warranty. I won't buy any mattress from them again.