Phone native to lower South West Mi. A week back I was traveling through a rural part of Indian and had a roaming signal but when I tried to make a call it asked for a credit card. Is this typical I was under the impression that there was a certain amount of roaming allowed.
the last time that this happened it was back in 1994 I was in Texas, went to make a call, and there was a request for a credit card. what was going on, was, I was connected to a small cell provider. and they wanted their cut. did not know that some of them are still around. so I would say, you were hooked up to a cell tower, owned by a small company, in rural Indian, and they wanted you to pay to connect you to the main network.
now having said that there are scam that intercept your call and ask for credit card, so you do need to know where you are and who is providing the cell connection.