Complaint - Matress People

I purchased a bed from the Mattress People in Clearwater, with memory foam and it first it was alright but then it started to sink in the middle to the point where I had to use blankets to try fill it. This horribly uncomfortable bed resulted in back and neck pain for both my girlfriend and I to the extent that we had to go a chiropractor for treatment. Eventually the Mattress People agreed to exchange the bed for another one. 4 months later the same thing is happening with the 2nd bed. I called and spoke to the manager who listened to the problem and promised to get back to me regarding a total new bed. I heard nothing since, after numerous phone calls which he ignores, no response/reply on WhatsApp. No update whatsoever not even 1 call. So at this very moment I sleep on a "new" bed less then 1 year old which I have to stuff with blankets & a yoga mat to try and support my back. I wake up with a sore and stiff back and neck every single day. I would like my new mattress soon preferably an individual coil one without the memory foam. I am exceptionally disappointed with the complete lack of service from The Mattress People.