Hi GingaNinga,
I think that post #2 here should be helpful and includes some of the better options in the area and some comments about them.
Mattress warranties are more of a sales tool than anything else because they all have exclusions that make successful warranty claims difficult and uncommon. They have little to nothing to do with how long a mattress will last. The only way to know the quality of a mattress is to know the materials that are in it and many retailers and chain stores and the major brands make it difficult or impossible to get meaningful information about their mattresses. This article may help you avoid avoid many the lower quality and value choices.
I’ll leave the choice of posting your “debacle” with mattress warehouse up to you but you are of course welcome to do so because it may help others who may face similar circumstances and may also help to highlight that almost all mattress warranties do not have the value that people believe they do. Buying a mattress based on the belief that a warranty is an indication or durability or quality or will “protect” you from foam softening or the loss of comfort or support that can make a mattress “unsleepable” can be an eye opening experience when the time comes that someone tries to make a warranty claim. The only way to have any idea of the quality or durability of a mattress is to know exactly what is in it.
Hope this helps … and feel free to post if you have questions along the way.
Phoenix