Hi river,
I’m sorry to hear that your T&N mattress didn’t work out as well as you hoped for but the good news is that you had the foresight to choose a mattress that has a great return policy so you had the chance to try it with little risk.
There are also other online options available as well that may also be worth considering.
The better options and possibilities I’m aware of in the areas in and around San Jose (subject to the quality/value guidelines here) are listed in post #2 here.
I don’t have a record of the specific mattresses they each carry so you may need to check their websites and make a few phone calls first before you visit any of them to make sure they have one or more mattresses on their floor that will fit your criteria.
Phoenix