There was an attempt by different phone companies to introduce metrocard which can be doubled as phonecard. In that case, customer could find on metrocard instructions and pin number to make a phone call. I know of only one real metrocard combined as phonecard and 2 preliminary runs which did not go into production.
Here is MCI metrocard/phonecard and an image of folder that metrocard was sold in.
Here are 2 others:
All cards have gold front side.