Unexpected $75 charge abroad

Hi,

I’m currently living abroad for 6 months and recently received an unexpected automated $75 charge from Xfinity.

I need help understanding what this charge is for, whether my account is still active, and why I am still being billed.

I would also like to cancel any active services associated with my account, effective immediately, and ensure that no further charges are made. However, I do not want to lose my US phone number and still want to receive iMessages to my US cell via WiFi. I need to keep my phone number for when I return to the US. 

I am unable to call customer service internationally, so I need assistance resolving this entirely online.

How do I review the $75 charge and receive a  refund? There is no customer service email to contact and Xfinity assistant will not connect me to an agent. 

Thank you!