I regret making this purchase.. I was promised it ...

I regret making this purchase.. I was promised it would be good for my 82 year old husband, who is having back pains and has a problem with lymphoma in his lower legs.
I ordered an XL TWIN, because I anticipated the need for rails later on,. the bed was too soft (HE SLIPS OFF) and didn't seem to be an XL TWIN. I called the next morning to complain to the company, but the Easy Rest customer service personnel was rude and indifferent to my problem.
This was by far most expensive mistake i have ever made, because my husband does not like the bed and I paid cash for it. The company said there is nothing they could do but to send out a topper for the mattress.
HOW DO THEY GET AWAY WITH THIS.