This is NOT Verizon. I called Verizon's 800 number and they confirmed for me that everything on my account looks normal, (which I already knew). This is a scammer. Do not answer and do not give them any information.
Verizon. They're getting sneakier...now they call from an area code where you live, instead of an 800 number. If you are getting close to your "cut-off" date (usually the fifth) expect a few calls a day from this number.