Sounds like you've been to the CZ USA website and know how to contact them about your sight problem.
My P01 Urban Gray front sight died a few months after I got it. I contacted CZ USA, they sent me the return info in just a few hours, I boxed it up and FedEx'd it to them. Took longer for it to get to them than it did for them to fix it and get it on it's way back to me. No issues since.
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Oh, I only shipped them the slide. No frame, no barrel/recoil spring/spring guide.