Non-Compete

I was previously workinbg for a radio company here in town in sales, I worked there for approximetly 5 months and things ended up bad there. The Sales Manager even after signing the Protected Account List for a few of the clients that I had he then allowed one of the "top" sellers to take possesion of these accounts after becoming discourage and frustrated I quit. I'm know working at another Radio Station in the same town and have recently been contacted by the attorney of the old employer stating that I signed a (non-noterized) non- compete agreement and that I could not work at my current employer for 6 months after leaving? Considering they didn't treat me fairly while I was there and I didn't get that type of consideration when they were taking accounts away from me and giving them to other co-workers how can they inforce this~ with this being my agrument do they have a good case against me I love my current employer and don't want to jepordize my job but I definetly don't want to hurt my current employer as well????