The driver agreed to waive the fare..if i didn't press charges

I was running late to an important doctor's appointment and the credit card machine in the cab wasn't working. I specifically asked before getting in the cab if he would take a credit card. After a lot of yelling and arguing about how I wasn't doing it right, he got into the back seat, swiped my card, and agreed the machine was broken. He offered to drive me to an ATM, but I was already late, and, after all the screaming, wanted to get away from him as quickly as possible. I got out of the cab, and the cabbie followed, grabbed my arm, and tried to take my purse ( I had no cash on me anyway). I had bruises on my arms for weeks. Luckily, someone driving by saw the assault, intervened, and called the police. The cops I'm sure had better things to deal with, and told me the cab driver had agreed to waive the $16 fare if I agreed not to press charges. I was so angry, but also still running late to my appointment, so I agreed, and the ordeal was over. I still wish I would have pressed charges against the cabbie--if he can assault one passenger, what is keeping him from doing it to others? I always thought cabs were the safest way to get around--not anymore. And while I don't know the driver or cab number, I will never ever ever take a City Service cab again.