That's technically unrelated to you using a website not intended for your actual physical location.

You see, there's a local credit card processing service set up on localized versions of latam.com. This is done to enable charges in each country's local currency (as well as enable payments in multiple installments, if it is something the local people expect) and help prevent the user getting charged for foreign transaction fees.
Each credit card processor will have its own rules for fraud prevention (some are simpler than others which are incredibly complex) but sometimes a payment attempt "in chile" with a foreign card, a foreign IP address, above a certain amount of money and with certain travel characteristics -such as being only oneway, or having less than X days of advance purchase, just to name some- may trigger the credit card processor's fraud prevention rules as a false positive. What the credit card processor does to you in those cases is most of the time up to them, not the eCommerce site you are using (this includes temporary blacklisting, which looks to be your case)

On top of that, latam.com does have it's own internal fraud prevention layer, which may also get picky and flag you when your purchase seems unusual.

Even more on top of that, your issuing bank may flag the payment attempt if it sounds unusual to them and, for your own protection, put a temporary ban on foreign payments for a period of time.

Couldn't know what exactly happened in your case, but it's probably something along those lines. Glad to know that eventually you got it to work