Like
FBinNY said there is no details on the problem. It could be something not the pedals is causing issues or it could be the pedals in which case the authorized dealer you purchased them from can start a warranty and get you new pedals.
MKS makes excellent pedals I have had two pairs of them and I have abused them and truthfully never maintained them (which I probably should eventually do) and one of my mechanics had Lambdas for years and years and years and years and I eventually bought him the Gammas because he had foot slippage and I don't think he installed them for a long time because his old pedals refused to wear out and he rode that bike everywhere for everything nearly everyday of his life and he probably had the pedals for at least a decade if not more.
If you keep running into "defective" products I would think maybe the products are fine and the person installing them or using them is the actual issue or it is possible you are just an unlucky lightning rod.