Declined credit card

I have tried several times to get this, using 2 separate cards which belong to me and are activated, but each time it said the card was declined. I am not overseas, I am in the continental US. I wrote an email a few days ago and still have not received a response. Pease help me with this.

Hi Greg,

What type of order are you placing? One-time order or subscription?

What type of card you paying with? Debit, credit card or prepaid card?