How do I get out of this job?

my dentist is offering me a job at his other office as a receptionist...first he said he wanted someone with experience b/c it was too hard for someone without it. then a few months later he said hed give it to me but wasnt sure how i'd handle it- basically b/c im laid back and quiet and the job is stressful, demanding and "ghetto girls" work there. that was in march. i havent heard about it until friday, when he called me and left a message asking me to call him back to talk about it. i never called him back. what do i do? i have to go in monday for an appt and i feel like hes going to give me the business for not answering,. what do i say? thx in advance