Make a payment error

I have the same issue every time I click "Make Payment".

ERROR. Sorry, This Isn’t Working Right Now. Please return to My Account Overview while we resolve the issue.

This has been going on for the last 2 months. It only worked for about a week and stopped working again last week.  I tried making payments using Chrome, Internet Explorer, Edge, all in private mode (incognito), as well as not in private mode. I tried clearing all browsing history, cache, etc. I used my Android phone, both in my home wi-fi, as well as using mobile network. Used the app, too. Rebooted my modem and router. Nothing worked. 

The Infinity ID is also not a problem, I tried checking that, too, using my home address.  

I would like to be able to make regular payments using my online account on the PC. 

Please help.