unable to make and receive phone calls in Mainland China

travelaround wrote:

Thanks- simply couldn’t make and receive calls

So texts and data is working? Does WiFi Calling work? If it does you should get on WiFi and call T-Mobile International Roaming Support at +1-505-998-3793.

This is why I suggest that international travelers have and know how to use a VoIP backup, like Google Voice, Viber OUT, Skype OUT, FaceTime, etc. .