We've seen it over and over again - a promo hits and the call centres get flooded, resulting in very long wait times for customers. I can understand why this happens, and so can many other customers. But, while this is certainly an explanation, it's not really an excuse - especially to people with more pressing issues (lack of service, account suspension, account cancellation, inability to log into Self Serve, etc.).
I'd suggest an implementation of a high-priority queue for these situations, not unlike triage in health care environments. Yes, everyone deserves (and will get) help, but not everyone's issue is equally pressing.