No cell phone mobile data at place of work

When I am outside of the building I get 1 bar, inside I get a message "emergency calls only" and can't browse the internet.  After spending way too much time on the phone with Xfinity customer service, many lunch breaks wasted day after day this is still not fixed.  They were supposed to do some line testing and fix it then call me back the next morning.  Unfortunately I was never able to receive the call back because both of my lines lost service after my phone call to them.  I had no choice but to visit the local Xfinity store.  They proceeded to give me physical sims instead of the esims that I had in the phones to correct this problem.  Now, not only do I still not get service at my place of work, but we can no longer text from the phones.  I have been at my place of work for 7 years and have had 2 different cell phone services in that time and have never had so much as a hiccup with either service inside my building. Furthermore, no one else in my building loses service when they enter.  
When I went to the xfinity store for help they said, "Why didn't you return it within the 2 week return period?"  First of all, I don't work everyday of the week, it took over 3 days for me to even discover the problem.  When I called customer service, they assured me it was an "easy fix" and they can have it working easily.  Which I believed because I have never had a problem in this area getting mobile data.  6 weeks this is going on.  Worst part is, now I have a 2 year contract with a cell service that doesn't connect. I was told by the person at the local Xfinity store that the only choice I have is to buy the phone out for $700 and take it to another carrier....really, that's the best you can do?  Going back to my old cell phone company and paying for a line with Xfinity that I can't even use. Customer service always promising this is what will fix it, and it never happens, they have no idea what they are even doing. I swear they google things to try. "Do a network reset, restart the phone"....if I hear that one more time I'm going to be sick.