T-Mobile prepaid not accepting new RBFCU Mastercard for payment - "card number is invalid"

So, this started on Monday 02/27/2023 and here we are on Friday 03/03/2023 and it's still not resolved. Whatever credit card service T-Mobile is using for their prepaid billing website and also their customer support staff obviously doesn't work properly. My guess is the web site and all of T-Mobile prepaid is run out of the country. Certainly the support staff is in Asia (I think the Philipines). This means that if you are signing up for autopay, then you are probably leaving your CC info on a questionable foreign server. Why do I think this? My credit card works with 611 and that service is run in the USA using authentication based in the USA. Think twice before signing up for autopay. I have 3 accounts I pay for on T-Mobile prepaid and using 611 to pay the bill is a hassle, but I'm starting to think that the risk of identity theft is too great when signing up for autopay with T-Mobile prepaid.

Also since T-Mobile have not bothered to even try and reach out to me to fix this, I'm going to consider other providers. Had considered their 55+ Unlimited postpaid account, but this has left a bad taste in my mouth and I really don't want to pay even more money each month to a provider that basically doesn't give a crap about it's customers. I also don't need an unlimited account - I barely use any data each month. I'll have to think about this.

Bottom line is, if you are using their prepaid plans - don't expect any help from customer service, they are useless. It's a joke - they can't even get their billing to work properly!