Xfinity Mobile international roaming charges while covered by Mobile Plus

Hello,

I travelled overseas with my Xfinity Mobile service. Prior to going abroad, I purchased Mobile Plus to cover my international usage. When I came back to the US 10 days later, I canceled the plan and reverted back to my original plan. Few days later, I received a bill for international roaming charges for almost $2,500. After endless numbers of calls, I was told the reason for roaming charges was because I reverted back to my original plan prior to the end of the billing cycle for Mobile plus, thus the system treated it as I never had international coverage while traveling.

Originally, when I called exploring the purchase of Mobile Plus, the agent told me it was ok to revert back to my original plan as soon as I return to the US. She never warned me about potential roaming changes if I chose to do so. Also, when I called asking to revert back to my original plan, I was never warned that I will be billed for roaming changes. I simply assumed that since I purchased the plan my international charges were covered. I simply did NOT know.

I refused to pay the charges and now Xfinity suspended my service causing enormous headache for me.

I think this is very unfair and I would like the company to review my conversations with the agents when (1) purchasing the Mobile Plus and (2) when reverting back to my original plan. Again, reps should have made it clear to me that canceling Mobile Plus and reverting back to my original plan prior to the end for the billing cycle would incur international roaming charges. 

I would like to request an investigation and to file an official escalation claim, and I want my service restored immediately while the investigation is pending.  Never felt this helpless..  My next step is to file a complaint with FCC and BBB but wanted to ask for help here first. How do I escalate this? Thank you.