body-dips after two weeks

I hate to rate this mattress so poorly, but the con just simply over-rides all else, Perhaps this is just one bad one and the rest are fine, but it's a failure for us due to the body impressions that are forming so quickly. Even though we find it comfortable, there's no way we can settle for a $3,000 mattress that looks 10 years old after three weeks, so we must return it and try something else. The nice salesperson was really surprised, saying he has never seen one come back and that all he could think of is that it's a bad batch of latex. He said they will take it back after 30 days of trying it out, or if the mattress collapses 3/4 of an inch or more, which I think it has. I guess we'll get another model of a PureLatex Bliss mattress, from a different batch of latex, and see what happens. If it also gets body-dips in it, we'll have to bail on the brand for something else.