ChargeNow not working in USA

We live in Canada. When we got our i3 a couple of months ago the dealer gave us two new ChargeNow cards to replace our ChargePoint cards. We have tried to use them many times during three trips to the USA without success. According to the technical support people at ChargeNow the cards are active and should work. But they don't. I just got off the phone with ChargeNow technical support once again. They are going to send us new cards. The error message we get is "card not authorized ".

Are there any Canadians out there that have been able to use the ChargeNow chargers in the USA?