I have used them for 10 years now for close to a 1000 bookings and the times it went wrong I can count on one hand; they also always help fixing the issue. Sure you get some bad VOIP connection (why is that still a thing...) but
if you just immediately push for the rebooking agent (which is separate from the normal support), you will be fine quickly in no time and at no cost. Unlike some experiences I had with booking...