I got a dropped call on a callback after two rings and the person who called hung up.
I also got a dropped call on another call back earlier the same day.
Verizon service reps have a habit of hanging up when they are busy and don't want to do a callback at 6 pm as scheduled or at 9:30 as scheduled. I am so disappointed. I waited on hold for so long during the day for a service rep after the customer service rep said he couldn't schedule a service visit for inside wire maintenance and said I had to wait on hold for another representative. I chose the option for a callback which never happened to my dismay.