I have never had one of those cards. How much money was on the card before they "revoked" it?

Is there an expiration date printed on the card?
Whomever you called probably won't be of much immediate help. At best you might be instructed to get a form from an agent (or download one) and then wait 15 days.
I did a google search and came up with the terms & conditions page:
https://www.easypaymetrocard.com/vec...ondtions.shtml
When I did a word search for "revoke", only this popped up:
If you use the EasyPay MetroCard when your Account is in a negative status, suspended or revoked, or after the EasyPay MetroCard has been reported lost stolen or damaged, you may: incur administrative fees; be charged the full, undiscounted charge; and/or be asked to surrender the EasyPay MetroCard to EasyPay MetroCard via certified mail or to plaza personnel.
Not helpful.
I went to the FAQ's and at best, I found this:
Q. What should I do if my EasyPayXpress MetroCard does not work?
A. When an EasyPayXpress account is not in good financial standing, the MetroCard will not work. Therefore, first make sure your EasyPayXpress account has money in it. If you believe your card is damaged, you can report it online at
www.easypaymetrocard.com or call our Automated Telephone Service 24/7 at 1-877-323-RIDE (7433). You are responsible for destroying your damaged EasyPay MetroCard after notification. Failure to destroy your EasyPay MetroCard may result in unauthorized EasyPay MetroCard use which you will be responsible for. We will send you a replacement card in the mail. Please allow 15 business days for processing.
https://www.easypaymetrocard.com/vec...pressFaq.shtml
Good luck and keep us posted.