Ok, I finally fixed my problem!!!
Apparently, my account was flagged as abusive and it was automatically suspended.
This means that I always had my Billing Info + Country A (let's call like this) and when I tried to change country (B), my billing info was wrong. When I tried to go to Country A, it started appearing these messages.
Apple also tracks the IP, so, when this happened, I had to ask Apple to unlock my account and then I should have confirm all my details from Country A being with an IP from Country A!
How I know this? The staff member at the Express Lane Support (live chat) told me everything.
Basically, I solve my problem in 15 minutes in the online chat while nobody helped me at all for 7 days by email support...
This is where you need to go: https://expresslane.apple.com
Then click iTues > iTunes Store > Account Management > Account Billing and then fill in all your details and choose the Chat option to discuss this with Apple Support. They are great, helpful and will tell you exactly what is going on with your account and hopefuly will solve your issue within a few minutes.
Good luck to all!
Joel