Here is the reply our content specialist has prepared for us regarding the issue at hand:
If you would like to make a MasterCard payment through AlertPay, please follow these instructions to do so:
1. Create an AlertPay account at www.alertpay.com/.
2. Validate your email address by following the steps in the validation email.
3. Login to your AlertPay account and add a MasterCard by clicking on “Profile”.
4. Under “Financial”, click on “Credit Cards”.
5. Return to the seller's website and click on the "Buy Now" button.
6. When prompted, login to your AlertPay account with your email address and password.
7. Change the source of funds to your MasterCard, type in the Transaction PIN and click “Send”.
Please note that this is a temporary solution to the issues we are experiencing regarding MasterCard payments.
Thank you for your understanding.