Good mattress but not so good customer service

I am a researcher by training, so whenever I buy anything I do extensive research. I needed a King mattress and I am a plus size side sleeper.I used to have a Sterns and Foster with a thick pillowtop that was great but their quality went down and then I tried an adjustable foam mattress for a couple of years but it just left me with shoulder pain no matter what I did. So this time around I tried Helix, Saatva, Casper (showrooms for the Helix, I had the Saatva for 80 days before I sent it back (great customer service). Eventually I came to Charles P Rogers. My initial ordering experience was good. The salesperson: Tina (Fulya)recommended the estate 9000 Luxury Plush King Mattress and so I ordered it. Between that time and delivery I almost cancelled however, there were hidden fees for things like delivery and setup and delays and I just about lost my patience with Tina and the company. Keep in mind I lived in New Jersey for 4 years so I am used to the quirks of the customer service in the area. Even considering that: the customer service was not professional or upfront. The only reason I went through with it is I needed a mattress (my old one was no longer an option) and due to time constraints, I needed to just go through with it. Just one example: their site says that if you put one of their mattresses on a non-Charles P Rodgers foundation it voids the warranty. Well, their foundations are ridiculously expensive. I talked to Tina about options and she told me just to order a generic foundation from Amazon for cheap. Well, I said: won't that void the warranty? Response was: I wouldn't worry about it. Well, I worried about it. And I ordered the one from Charles P Rodgers because I was spending $3000 on a mattress and wanted to make sure the company would stand by their product. Fortunately, 6 months later the actual mattress is literally my favorite piece of furniture in my house (and I have some nice stuff) as it is just perfect in terms of comfort and support. I am happy I went through with it-- but I am concer