Does anyone know how I can resolve an issue with Amazon Prime?

[c=#800000]I have text chatted with them, I have called them three or four times and I have written to them several times. They keep telling me there is a problem with my debit card. However, just the other night I rented and streamed a movie without an issue. Then, a day or to later they rejected my Prime enrollment for the fourth or fifth time. I have been trying to get this resolved for 2 1/2 weeks. I have no idea what to do. [/c]