I have a 2008 Chevy hhr in two days after I had bought it I have to take it back and have them replaced the speakers we're blown at ford in bartlesville while it was still under warranty every since then the key fob will not not work in the key will not unlock the doors

 

Welcome to the site, Lisa! Most likely some wires were left loose when they repaired the speakers, they'll have to fix it!
I have to ask why dig up a 9 year old dead thread, instead of starting a new one or may I direct you to the search window, there are tons of threads in regards to your door lock and speaker issues. But I glad you at least asked

 

Moved these two posts from a discussion on how easy it is to break into the HHR.

They are no more difficult to break into than other vehicles, if that is what you are asking. But we aren't going to discuss how to break into an HHR here for obvious reasons.

If you are currently locked out of your vehicle due to work the dealership did - call them and have them resolve it. If you are able to get into the vehicle and are handy with tools etc., Oldblue offers good advice - look for wires disconnected under the dash, leading to the doors.