Windows and signal lights, ok tire says rely control module

I had put the car into Ok Tire the 17th of nov 2014 and went to pick it up Tuesday, so I drove it there everything worked fine I have never had an issue with the car ever before, but I was getting new brakes routers and calibers, and new tires and rims, a transmissions flush, fuel enjection service, and an oil change as well.
they went to bring the car down off the hoise the windows would not go up and it was a snow storm out side, so they tried to trouble shoot it and figure out what the issue was and had no luck, I refused to take the car in less shape than I dropped it off, none the less they are telling me its my problem not theres I pick the car up tomorrow, and they say its the rely control module, and when they tried at first to contect the computer they couldn't connect to the windows, and the signal lights don't work, offcourse they checked the fuses im sure, I asked, so im pretty sure they did, my backround is electrical generation systems techican for the air force, and just recently transfer to an air craft structure tech, so im pretty mechanically incline, and very familiar with wiring diagrams, but I cant find one to see if the two are related and I have no clue if they could have actually did this damage and maybe is there something else that may make this module act like its broken, id hate to replace it myself and have it be something furthure down the line and have the new one not work as well, as I am getting ready to go home for Christmas after a year and really counting on this car to be in great shape, after paying 3500 I expected it to be in great shape leaving not come out a klunker!


Ray