Now Mobile service date and billing error

I have wasted 3 hours with telephone bots, chat bots, and 7 or 8 customer service agents from every other dept team because there is no way to contact Now Mobile Billing support.

My Now Mobile Phone Service began when I received delivery of phone, activated phone, and transferred phone number from Straight Talk on Feb 11. Xfinity is cheating me out of 4 service days by setting my service date as Feb 7. I had already prepaid Straight Talk through Feb 19. 

I don't mind losing 8 days of prepaid Straight Talk service. But Xfinity cannot include 4 days of service when I was not a Now Mobile user until Feb 11. I placed the service order request on Feb 7.

Please correct my service begin date to Feb 11, and to the 11th for all future billing/service dates. 

Btw, I cannot be contacted via Comcast email because I never used it.