Audio questions

Hey all i have 1 single question and a story to back it all up. I recently (tonite) bought 6.5 speakers for my front doors since they were burnt the week after i bought my car on oct 04. OK after i bought the car i replaced the back 6x9's and a new amp to run it. I told audio express to not worry about the front speakers since it dont work. I think they did something so that it wont work ever again. Now today i tried installing the speakers in the front and it dont seem to want to work. I can hear static but no sound. What do u guys think audio express did? Or can i undo what they did? I know for sure they hooked up RCA outlets to my stock infin deck. Please help because im getting a new deck tomorrow too.