Hi aviator79,
I’m sorry to hear that you aren’t sleeping well on your mattress. I would also be interested in the content of your review that was removed (using terminology such as “scam” or other inflammatory language is sure to get your review removed from almost any manufacturers site).
In all fairness I certainly wouldn’t call their warranty a “scam” because all warranties in the industry only cover manufacturing defects and don’t cover comfort issues such as choosing a mattress that is too soft or too firm or foam softening which leads to the gradual loss of comfort and support over time unless they also have visible impressions that are deeper than the warranty exclusion (which is usually between .75" and 2" with 1.5" being the most common). Their warranty actually has a smaller exclusion than most manufacturers in the industry. There is more about mattress warranties in post #174 here.
Unfortunately it’s not possible to “diagnose” mattress comfort issues on a forum with any certainty because there are too many unique unknowns, variables, and complexities involved that can affect how each person sleeps on a mattress in terms of “comfort” and PPP (Posture and alignment, Pressure relief, and your Personal preferences) or any “symptoms” they experience but there is more about the most common symptoms that people may experience when they sleep on a mattress and the most likely (although not the only) reasons for them in post #2 here.
The most common reason for lower back pain is a mattress that is too soft or that has developed soft spots or sagging in the foam under the heavier areas of your body (typically the hips/pelvis). This would also be more likely with 3 lb memory foam which is generally a less durable material than higher density memory foam. I would also make sure you check your support system under the mattress isn’t the cause of your issues (you can do this by putting the mattress on the floor for a few nights to see if it makes any difference)
If your mattress either is or has become too soft then there are some suggestions in post #4 here that may be helpful (including flipping it over but you will likely need a topper if you try this).
While a topper can certainly help to soften up a mattress that is in good condition and has no soft spots or sagging in the sleeping surface and just needs some additional softness or pressure relief … it’s much more difficult to firm up a mattress that is too soft or that has developed soft spots or is sagging because a topper will generally just follow any sagging or soft spots in the mattress underneath it. At best a firmer topper may provide a partial or temporary solution and at worst it could make things worse (it could make the top layer you are sleeping on too firm in terms of “comfort” and pressure relief and the layers underneath it may still be too soft to provide good support/alignment.
Phoenix