Hi venexiano.
Thank you for visiting The Mattress Underground(TMU)! 
I am sorry to hear that your mattress is unsuitable and that are waking up sore.
TMU is not opposed to the main bedding brands, nor companies like the Mattress Firm. The major manufacturers generally tend to use lower quality materials in their mattress that will tend to soften or break down more quickly than the higher quality and more durable materials that are used by many smaller manufacturers. This is why it’s so important to make sure that there are no lower quality materials or weak links in any mattress you are considering. There is more about the quality/durability guidelines that I would suggest in post #4 here. We do, however, recognize that there are high quality, value mattress alternatives for consumers such as TMU’s Trusted Members
Based on your note, its high sense of urgency, and assuming that you want to be able to go to a retail store in the Gainesville, FL area for your purchase, the Mattress Firm may be a good alternative for you. The Mattress Firm has changed its return/refund policy and this may provide you with post-purchase options, at a nominal fee if you do not find the right mattress for you if you choose to make a purchase.
Good Luck with your selection!
Phoenix