I have had the EXACT same experience. Customer since the 90s, and I remember when calling their customer care meant actually talking to trained, professional, helpful individuals that could sort you out. The stores have always been kind of iffy but I remember the service line helping me out with ease before. I have had such a stressful experience with a recent issue from the store to the customer care line, through an already very stressful situation in my life. I am on a family plan and once my device is paid off I plan to break off and take my business elsewhere, unless Verizon customer care changes for the better before then. And to answer your question, the only way you can is to call their 1-800 customer line and say you want to complain and document your issue so they can supposedly handle it internally, and hope you get a caring individual that won't be upset at you for wanting to do so (like one of the reps I talked to was).