Diamond Parking used to send me to collections all the time. Probably because I never paid them. They'd call up and say "You owe Diamond Parking $180" and I'd say "you're charging 400% interest on a $40 debt that you bought for $3 and the sun will be a cold dead cinder before I give you a dime. But I'm happy to call you names and tell you terrible things about your mother for as long as you want to stay on the line. Pyrrhic victories are a hobby of mine and I will gladly add your scalp to the collection." Fuck Diamond Parking and anyone who buys their debts.
I used to get calls from debt collectors about my mother's medical bills. Not even my debt. My solution was an Asterisk box that would play /dev/random on demand, then call them back and do it again when they hung up and keep going for an hour, then remember the number so it could answer and screech white noise for an hour automatically if they called back. It took a few months, but they stopped calling me.