pushes their useless "Worry No More" insurance

we went to buy a boxspring that broke. we ended up buying a whole new mattress set. THat in itself was not the problem. the problem is that they pushed their "Worry No More" warranty that turned out to be completely useless. They also said that mattress manufacturers will deny warranty if we use a competitor's box spring (this turned out to be completely false... We should have realized that some people don't use box spring on a platform bed.. manufacturers can't void warranty just becase they don't use a box spring, how can the void warranty if we use a different boxspring?). During the first 90 days they have a full replacement guarantee. but about 100 days, the box spring started to make a lot of noise. when we contacted them for warranty they complained incessantly that we should have contacted them 10 days earlier. They eventually sent someone to test the defect, and ordered a replacement under warranty, but it was not a very pleasant experience dealing with it. The mattress they sold us eventually developed deep enough body impression to give us daily backaches, but they were of no help.