MBps Fraud - Getting a technician

I am going to try and describe my issue as calmly as I can but I am having a hard time calling this anything else but fraud.

I recently moved into a new apartment and signed up for Xfinity, the only provider I could chose from. I bought a MG7700 router for myself because I was tired of renting out routers from Xfinity. I signed up for the 400 MBps plan and when I first connected my new router with the Coax cable and tested the internet speed I was shocked seeing a download speed of 25 MBps. 

After calling Xfinity and them having me restart the router for three times they finally told me to call Motorola (router company). Ok, I thought, fair enough, might be the router. 

After troubleshooting there and looking at some logs no issue with the router was found (as I expected, since it was brand new) and I had to start from square one again. Another round of talking to incapable Xfinity Reps led to nothing and my internet connection got WORSE. 

I ran speed tests yesterday throughout the day and the download speed does not exceed 10MBps. Now I am aware that the fine print says UP TO 400 MBps but that discrepancy is absurd. 

What can I do to have a technician come out to my address (I live in an apt building) and making sure all the cables and wires are connected correctly? I am 100% sure this is an Xfinity issue that has nothing to do with my router and am typing this out in the hope to be heard and my issue is being looked at.

Please advise!

PS: I didn’t see an option to attach files but I can attach screenshots of the speed tests that I ran.