My personal VISA works fine, but we want to use our business account which is Mastercard. How do we setup billing with PayPal?

Our Mastercard debit card is not being accepted for billing by Shopify. Our bank says that Mastercard won't work with Shopify because of the high number of fraud transactions. They told us to contact Shopify to find out if there is another way to pay...

There are not any contact options there. Yes, trying to pay for a subscription.  Can you call or email me? 

I am setting up a new account and am having trouble getting the system to accept payment. I have tried three separate credit cards with no luck. Is there a way to reach customer support by phone or chat? The free trial ends today.