Tanzania E-Visa Application - Payment Processing Problems

Hi everyone! I have been trying to apply for a Tanzania e-visa for about 3 weeks now, but when I enter my credit card details and try to pay, I have been receiving the same message that payment is unsuccessful. I have called my bank to see if the issue lies with my credit card, but they can't even see the attempted transactions and believe it's with the payment vendor. I have e-mailed visatanzania@immigration.go.tz but haven't heard back. Is anyone else experiencing this same problem and has had any luck resolving it? I would really like to avoid having to get a visa upon arrival. Thanks so much!