Service turned off

So xfinity is charging me when I had my service added it was supposed to be the year of service free and I got my phone for free I just had to pay tax on it which I did well they cut my sevice off and told me that the xfinity employee didnt apply my promotion cold so I want to know who to talk to about this because the last person I spoke to told me that I was going to be credit for the inconvenience but yet my service is still off and they are now trying to take sixty something for the reconnect and still trying to charge me forty something saying that its for my phone which was free