Hi, we would have liked to help you out if you had any concerns with the mattress, but this is the first that we are hearing of any issues. Returns are not a hassle, or you would be reading all about it on our reviews, so we definitely make them as hassle-free as possible. As for comparing our mattress to another companies Firm mattress, all firmnesses will be different since there is not a universal standardized firmness measurement. For any concerns with getting the proper model and firmness, we highly recommend you to reach out to us so we can factor all the variables.
We noticed that you ordered a Twin mattress. We typically only recommend twins for children and if you have been having the same issues with multiple vendors, we would highly recommend you go with a Full size. With the twin having the Firm-Edge support, and if you are an average to larger-framed adult, it's possible that the middle simulate feeling a little lower than the edges. Please feel free to contact us to see if we can process a return or exchange. We have not had any complaints about our mattresses sleeping hot, so there should not be any concerns with that. Thank you.