Hi nancymariec,
It’s unfortunate that you ended up returning your mattress (and buying a much lower quality and much less durable mattress) because there may have been some options that may have helped with temperature regulation (see post #2 here). You may also have been better off exchanging it for another mattress from Parklane that slept cooler for you.
In any case what’s done is done but you may now be in a very difficult situation because the store you purchased from may not have any good quality options to exchange for.
If you let me know which store it is I can look at their website to see what they carry but I would be very cautious about a “latex mattress” if it is made by a major brand because it may also have significant amounts of lower quality materials (such as polyfoam) that could be a significant weak link in the mattress. Hopefully they carry better quality latex mattresses that don’t have any lower quality materials or weak links in their design.
I would always try and make sure that to the degree possible you find out the type and quality of all the materials and components in any mattress you are considering as an exchange (see this article) so you can avoid a mattress that starts sagging or develops soft spots much too quickly after a purchase because of the softening and foam breakdown that is the result of lower quality materials in a mattress.
Post #2 here also has some suggestions about the two main strategies you can use when you are in the unfortunate situation where you need to exchange a mattress at a store when you are they may not have any particularly good quality/value mattresses to exchange for.
Phoenix