Wrong modem on Xfinity App

Hi,

I use an arris surfboard for my modem on my account. A technician came to my apartment to activate it and since then I have had a random modem in the app that I have never used before. I don’t believe the correct modem is activated as the modem type, wifi bands, and passwords are all incorrect. I have tried contacting support via phone several times to no avail and I am running out of options. Can someone please help me resolve this? My internet quality has been below par for the past few weeks. Thank you.