I'm not sure- I know a few people have been having issues with the site as of late. You said you're using Firefox, did you try clearing the cache and cookies? What about trying out a different browser?
I'm terribly sorry that you spent the time trying to reach out to messaging and they could not help. You might want to look at reaching out T-Force via Facebook or Twitter (after you've cleared the cache/cookies and tested another browser) to see if there's something wrong with the website and if a ticket needs to be filed on your behalf.
Sure did NOT help. manage.my.t-mobile.com will NOT allow credit card payments. Clicking on "credit card" brings me back to the account summary screen, then takes 2 minutes or more to get back to the payment options screen. t-mobile account management web site is badly broken.
I've been on the phone now with T-Mobile Cust Service about 25 mins, agent got the CC card no. wrong twice, got my account no. wrong 3 times, got my address wrong 3 times, got my CC card CVN no. wrong twice.
CC payment won't go through, got my address wrong again? Yes. Fourth time to explain how to spell the city.
31 minutes to finally get my payment posted. This would have taken about 90 seconds if your web site were working.
Please keep in mind that I'm your customer, not your employee. Show me proper respect by NOT wasting my time and show me the proper value you are adding by servicing my mobile communications needs.
I switched to Chrome, and everything worked. Sigh.
Thanks magentatechie for the tip to try another browser... should have thought of that, like "when in doubt, reboot."