Santos, instead of buying a new relay, just pull the cover off the fuse block under the hood, and pull one of the relays from there for testing purposes. They're all the same, so before you go hunting down a replacement, make sure that the one you have now is actually the problem. If that fixes it, then you've just got to get a relay. I'm sure you can get one at the dealership, or most parts stores, or someone here can mail you one that has a parts car.
Odd that a car goes in for a water pump and a timing chain, with a working top, and comes out with a non functional top. I would have taken it right back and asked what the hell they did to it. I highly doubt that it was merely a coincidence. <_<
Also make sure that the switch hasn't gone bad. Are you sure there's no power at the switch? Could it be possible that the contacts just aren't touching each other? We did have a guy on here only 2 - 3 weeks ago that had a power window problem exactly like your top problem, and all the same symptoms, and it turned out he didn't check the switch contacts after all.