If by "with hold" you mean "cancel" then I agree... I hope you do testify. I would love to see the judge say "Oh? Is that so? A company chose not to do business with a customer and gave them a refund? And your point again? What's that, the only point you have is on top of your head? Get out of my court room you idiot."
Yes, by your own remission you stated that it's more profitable to cut ties with disgruntled clients then keep them on, but when others followed suit you cleverly ceased said practice, ergo discriminated against at least one.