Over the years I created relationships with several folks (all key accounts). When I was laid off, I proceeded to tell them all how FIS instructed me to hide SLA misses and breaches at every available opportunity. I didn't tell them NOT to renew, I just told them to be sure they explored all available options.
But honestly I didn't have to do too much. The product was cr-p on a fancy plate.
I'm hoping that it hurt.