You must of lucked out when you called, I have been trying to call that number all day and they keep telling me all reps are busy and hanging up. They aren't even giving you the chance to wait on hold for someone to be available.
I also can't get a hold a rep by calling (877) 247-3846. I did trying to use Verizon Trade in "contact us" form twice but haven't received a reply back in over a week
This EXACT same thing has happened to me. My contract was over I could have easily switched to any other company but stayed with Verizon because I had appreciated them to date. However, this makes me sick. I was expecting that money. $36 instead of $200! Absurd. I reset my phone, removed it from the cloud, you name it, everything was done. I hope someone with the means to do so organizes a class auction lawsuit. They aren't even answering calls on the call in line.
If you still have the IMEI number, go to the Apple Activation Lock iCloud site and plug in the number. If will show that the device is unlocked. I've been waiting 2 weeks to hear something back on the rebate. Wish I had just walked it into the store. I did a factory reset, so if they claim the device is locked the Apple site will show otherwise.
Got my $200 Verizon credit in store.
Took a while, they inspected the phone very closely. In the end they gave me a receipt with a gift card number on with worth $200 credit at Verizon.
Now this is a bit different then what I have been hearing. Some are reporting getting $200 Visa cards that can be used anywhere. I did not care though as I was planning on using mine to pay my bill anyways.