$100 cancellation fee dispute, Xfinity failed to provide service

I had a plan with xfinity for over a year and then I relocated to a new place in Knoxville TN. I immedeately ordered my services to be moved to the new address giving all the details. I was working from home so having internet connection was crucial. For three months Xfinity people at knoxville didnt move my services, I even paid for the modem for one month because it was just sitting in new house without any connection. I had to switch to a new service provider because of this pathetic service by xfinity. And now xfinity guys are charging me with $100 of cancellation fee. Its not because of me i had to cancel the services, its because xfinity failed to provide me service for three months. What was I supposed to do? I had to cancel it. There is no way I am going to pay $100 charge. From what service I have been provided, I dont think I will recommend Xfinity to anyone. Why does it takes three months for xfinity to transfer services? what are customers supposed to do in that time? we have work to do. If xfinity has any shame left they should take back that charge.There is no way I am going to pay the fees, I will fight till they accept their mistake. Anyone faced similar issues?