In brief: we were without service for 16 days in July 2018. Following restoration of service, we still had intermittent problems until our low-voltage service company intervened. One issue continues to this date (August 12). I can elaborate further, and will supply a detailed timeline if needed; please advise.
This is primarily a peer-to-peer public Community Forum. You probably need to call Customer Service at 800-XFINITY (800-934-6489), unless you were looking for sympathy from other customers.