Bests & Worsts Reviews from Amazon

I am a musician/concert goer who wants to protect my hearing in loud situations while hearing the (high frequency) clarity that is lost with foam earplugs. While these were advertised "reduction in sound levels evenly by 20 db without changing the clarity" I found that they barely cut back sound levels at all when worn. To add more frustration on the back of the packaging it says "Noise Reduction Rating of 12 decibels" (not 20). When I tried to return to Amazon I found out that it's a "non-returnable" item! Had I known that in the first place I wouldn't have ordered at all. When I spoke to someone in customer service they said I should order another pair and see if the results are the same . . I thought REALLY? I've always been happy with Amazon prime & in this case they told me just to keep the earplugs and they would refund the $ which they did. I would have rather gotten a return authorization so that other users would not have this aggravation. I have attached a picture of the verbiage on the back side of the package.