Hi Sweet Dreams,
I’m sorry you had difficulty in getting replies from Paramount Sleep. I don’t know that this is normal for their customer service (other members here of the site have received replies from them previously), but they generally don’t share the densities of their polyfoam (they consider it “proprietary”).
When making a purchase, I would be cautious with buying from liquidation or clearance stores like The Dump (see post #8 here) and at the very least I would check any mattress carefully for any evidence of use and make sure that it has a manufacturers warranty.
Phoenix