I bought a phone from Comcast that stopped charging properly

The phone isn't charging properly so I was instructed to take it to a local repair place here in town called UbreakiFix and they told me they were unable to repair the phone and I would have to send it in so now I'm going to be without a phone for over a week possibly 2 weeks and they don't have a loaner phone or something that was mentioned to me by Samsung. So now I'm going to go without a phone and they're not willing to replace the phone. I don't want another one of these phones but I still owe on it apparently so now I'm stuck with this phone or the repaired phone that will probably break down again. I called Comcast and asked for some assistance with this and they said unfortunately they can't help me and blah blah blah so now I'm not sure how to proceed. We bought a second phone from them until this one other one could get fixed but my mother needs this phone and we plan to transfer her number from her other company over to this one so that we have both of our phones with Comcast. They said they would charge us the price of one bill for both phones each month but that's not really going to work until I can fix the problem with the first phone