Let's talk about timing then!
So *611 texted me saying to try to pay again and then if unsuccessful, call the credit card company. I wanted to post a message here to read what some of the community might say and also, I couldn't imagine why there would be an issue with my credit card. Then, I thought, while I am waiting to hear back from PM Customer Support, I should just call the credit card company... it doesn't matter if I can't imagine there being a problem with my card.
I learned something interesting: After my last credit card transaction, which was at a restaurant that I usually go to for the non-exorbitant amount that I usually spend there, the credit card company put a restriction on my card "to verify that it was actually me making the purchase". It just so happened that my next transaction was to be my payment to Public Mobile! So once I acknowledged that yes, that was me and verified my info with the credit card company, they removed the restriction on my credit card.
So now I am subscribed to a plan and have successfully made a payment on Public Mobile.
Thank you again everyone for your quick and helpful responses. Thank you Public Mobile for your helpful *611 text. The CC company wouldn't give me a more satisfactory answer as to why they put a restriction on my card just right now, but I am grateful that I called them and that all is good.
I appreciate everyone's support and will accept this post as the solution.
