Can I decline a job offer while in Navy DEP?

I signed to the Navy under the A-Pact, the airman pact. Now they say they have found me a job, which is ABE, and hell if I'm taking that. I refuse to sign anything for that job. My recruiter said the Navy already changed my job from A-Pact to ABE at MEPS automatically. Can they do that if I haven't authorized to accept, and haven't signed a new contract with that job? I am suppose to head over to the recruiting office so they can talk to me about how everything works, but I am going to refuse to sign. They even said they automatically changed my ship date from June to October. I know they can change that but do they have the right to change my contract without my signature?