Call Verizon's 800 number. Enter the 7 circles of heck, then wait even longer. Hang up because you've been on hold so long you have to eat to stay alert. Call back in, then enter the 7 circles of heck, then wait even longer.
Unfortunately this is the only way to disconnect a line of service permanently if you aren't going to transfer it to another carrier.
To cancel service or remove a line permanently: Call Customer Service at (800) 392-0717, (Mon – Fri, 7 AM - 9 PM, Sat – Sun, 8 AM – 9 PM local time).
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.