I called Tesla on 01628450660. Although, other than a roadside issue - its appears to be a Monday to Friday affair for support.
Thanks for the the number. I called them on that number this morning and the agent cleared the "UI customAlert100000 Scheduled at EU-UK-GlasgoW" alert message and set me up with my free month of Premium Connectivity.
It was all working when I went out to the car about twenty minutes after the phone call.