Product: Credit card or prepaid card

I've been trying to make purchases online in XXXX with my U.S. Capital One credit card. They put a block on my account. I understand that they were concerned about fraudulent charges on my account. Up to that point, no problem. 

They asked me to call them to confirm that I had made the purchases, which by the way were less than {$500.00} and on XXXX, a reputable site some might say, with their own security protocols, and where I've used the card in the past, the only difference being that this time it was using the same account but on XXXX 

I have their Capital One app on my phone and access to the account on the computer, both of which require login and password. That alone should have been enough to unblock the restriction placed on my account. But they required me to call them, so I did. 

I answered their questions and asked them to unblock my account. They said they needed to send an SMS code to my phone ; and therein lies the problem. As I spend much of my time traveling ( I work XXXX - even before the pandemic ), I no longer have a U.S. based phone number. I have a data SIM card with a XXXX number. I spent most of last year in XXXX and I am now in XXXX. The old U.S. number I had no longer works. 

They would not unblock my account without a U.S. based cell phone number. In fact, I've noticed other companies using a U.S. based cell phone number verification system as well, excluding the possibility of other country code phone prefixes, while not offering other options for verification, or making it very cumbersome to verify one 's account in a different manner. 

Since when does a U.S. citizen need to have a U.S. cell phone number in order to function normally in an increasingly globalized economy with more people spending long periods abroad? For that matter, since when is a person required to have a cell phone at all? What's the next step? Pinning us down and inserting locator chips? 

The first time I called, the Capital One representative was not helpful. She was rude and would only unblock my account with ID verification by email, which would take several days. I agreed to this ; however, she didn't even do that. I never received the email. 

Upon calling a second time, I got a Capital One representative that told me she had managed to unblock my account and that I could now make purchases online while abroad. I asked her to put a note on my account that I'm in XXXX and to allow purchases while here. She said she did that and everything was good to go. 

I then tried to use my account, but it didn't work. The restriction continued. So that Capital One representative, while polite, basically lied to me. I called again, this time angry. After going through the entire rigmarole again, I did their ID verification by email and am still waiting for them to unblock my account. 

I feel that they are abusing me as a client. My credit is excellent, over 720 the last time I checked. I have no debt - none at all. I always pay my balance in full, and I'm starting to believe that's the problem. I don't make them any money. When I suggested closing my account, they were ready to do that on the spot. So I didn't and decided to contact the CFPB instead. Hopefully, you'll be able to resolve this issue for me. 

Sorry for the long explanation. Thanks in advance for any help you can offer.