Sleep on the couch but don't buy Serta

I bought a Serta mattress about four months ago and paid $400+. Just with in these four months the bed has developed bowing in the middle and that too with a 150lb person who sleeps on that bed only two nights a week. What a waste of money. As ofcourse my 30-day return policy has expired, all I can do with it is throw it in the guest room. Buying Serta was a waste when I saw so many a little bit more pricier Sealys. So I would rather prefer to sleep on the couch than to ever consider Serta again. If still any sane Serta employee reads this please remind yourself what a customer satisfaction means.