1) customer clicks pay
2) redirect to your payment page and it shows the price of his purchase in BTC, then
Offer them two options:
1) do you have btc to pay
If Yes >> then pay and checkout
If No==> buy btc instantly (auto fill amount same as his purchase value) ===> sell him same amount of btc by credit card
After btc purchase is completed then redirect him back to our site for his final purchase confirmation and confirmation email will be sent to him.
Goods will be delivered to the customers and they will be updated by tracking numbers.