It sounds like you called billing, or some other day time only dept. try this instead "Our agents are available by phone 24/7. 1-800-XFINITY (1-800-934-6489)"
So the network drops out for a few hours then its back BLAZING fast. My guess its they swapped out a router or something? dunno. but its working. Pretty crappy to have a complete loss of service tho..