Front seat speakers not working in my truck?

I have a 1992 toyota 4runner, really good shape, and my dad got me a new stereo in it at Car Toys. All the speakers, amps, all that replaced and a new Alpine Stereo. So he did this about a year ago. (got my license 5 months ago, then he gave me the truck then) and now the front 4 speakers in the front seat do not work. Just the back seat/ very far back speakers work, and I dont know why. My dad said maybe the connection came loose. So should I take it in to Car Toys, and will they fix it for free? Because I hate listening to the radio and feel like I am passing the music because its coming from the back. So does anybody know why the speakers dont work, and should I take it in to get it fixed? Thanks for the input!