Hi gmike41t,
I don’t blame you at all for being both frustrated and angry. I would be in a similar situation as well although it doesn’t particularly surprise me with a hotel mattress which is a different sales channel from their “regular” mattresses.
This is more of a legal question than anything else and I don’t think I would be qualified to provide advice there but I would certainly pursue it further and let them know that you believe in no uncertain terms that they should abide by the terms of their original letter and that you will be doing what you can … including filing a complaint with the state attorney general’s office, the BBB, and online forums … if they are not willing to keep to their original commitment. Of course they are not generally as responsive to customer service issues or customer complaints as smaller companies. Your best odds may be applying some pressure … with the actual intent to do what you are saying … in the hopes that they will be more reasonable and ethical.
A full topper is only a good idea if you need to make the comfort layer thicker or softer. While it’s true that a topper can increase the durability of the foam below it … if you add a topper to a mattress that already has fairly thick and soft comfort layers then you could be creating additional alignment issues because you will be further away from the support layers of the mattress and could turn the softer comfort or middle transition layers into support layers and they may be too soft for that type of use. A topper is only really useful or suitable if the comfort layers are either too thin or too firm.
Having said that … it may be a good idea to add a thicker mattress pad which will have less effect on alignment than a full topper and will also help the foam below to be more durable. This is what the hotels themselves often use to extend the durability of their mattresses. While there are many options here with many different types of materials including cotton, synthetic, and natural fibers in many different thicknesses … wool would make a good choice because of it’s ability to help with temperature and humidity control and its natural resilience. Like all fibers it will compress over time (about 30% of its thickness) but then it will stay about the same and this is normal for a natural fiber. There is more information about this in post #10 here.
I hope you let us know how this goes for you … but I really would “go up the line” as far as possible.
Phoenix