Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Eh, not what I thought I was buying

I bought a pair of insoles from these guys a while ago and I thought this was the same product. It wasn't, but based on the good reviews I figured, my father, with bad knees, could use the arch support to help relieve some pressure. Instead he back started hurting after a week of use. He gave them back to me, I tried them for a day and they didn't do me any good.I prefer the hard plastic insoles with arch support, which is what I got last time and still use today.