DriveTime Automotive Group

I have been getting voicemails from [protected] requesting callback at cell number provided by agency I do contract work for. Calls have been going on for months. I and agency have never done business with Drive Time. I've written to Albuquerque office listed for that number requesting they stop. They continue.
I've tried to contact Drive Time national office. No mailing address is listed on the internet site. When I try to leave a message at the internet contact us form, it is consistently rejected due to length, no matter how few characters I use. I will not fax them or give them an internet address or other phone numbers to endlessly abuse. So, I'm left with writing Albuquerque again and then sending copies to Better Business Bureau, phone company, or whatever else might be appropriate.