Need to return unopened mobile phone

When I was using Xfinity Chat to check the status of my service appointment, the chat person said that while we were waiting she wanted to see if she could save me money on my cable bill. Obviously I wanted to see what she could do, but I ended up getting talked into receiving a "free" mobile phone, even after telling her I was locked into my carrier with my phone until it was paid off over 2 more years (a promotion I agreed to through AT&T to get the lowest price). The chat person insisted this would be a charge of $8.33/month that would be credited each time, making it free. Also, the $20/month for the mobile line that I would NOT even be using would be fine because this would somehow make my cable bill $50 less per month. I am finding out now from an Xfinity store rep that we did not qualify for this promotion because they did not port my phone # over so the phone was not free and the less I'm paying per month is just because I sacrificed many channels that we had and lost by now signing a new promotion to lower the bill. 

At this point, I REALLY need to return this unused, unopened mobile phone that I received and cancel this mobile line until I am able to actually switch my current phone over. I am paying for a phone that I didn't even want (I am an iPhone user, not Samsung). I feel taken advantage of by the chat person because this was not in my best interest at all and I am left with paying for services I did not need OR want but was tricked into thinking this was what was needed to lower my overall bill. We are over the "14 day period" to return the phone but please allow me to based on the situation.