Then you need to replace them. Resurfacing will not cure a warp. It may make a temporary improvement, but as they are now thinner than before, by the amount of material removed, they will warp again, very quickly. Once warped, the metal develops a memory effect, and wants to stay that way.

I have never had rotors resurfaced. If they are of adequate thickness, and not badly scored or glazed, I just replace the pads. If the rotors are too thin, or have other major problems, it's time for new ones. It might be a different story on something like a 122, for which new rotors can be expensive and hard to find, but that is not the case with 240s.