Can I cancel my 5G MiFi M2000 hotspot account?

I added a line to my account in roughly 7/22 to support a Zoom meeting we were having in a facility without WIFI. This worked fine until roughly 1/22 when it failed miserably. We were having bad weather that week but found, after that week, it never worked sufficiently to be useful again.

We updated the firmware, checked for best signal strength (we always had at least 3  bars) and all other options and finally sought out another solution.

I now have a 5G MiFi M2000 that I’d like to return to T-mobile as it’s useless to me.

I can find no way  to do this on the website. I still have ~$200 to pay off this device.

1. If I go to a t-mobile store (inconvenient for me), what can I expect?
2. Presuming, at the least, I will be "stuck" with the 5G MiFi M2000, is there a market for these? Where can I get rid of it (e.g. eBay?, other options?)

Thanks in advance for your help...