I'm trying to buy archeage Unchained at a discount, but I'm not getting it. It gives the following error:

We're really sorry about this, but we're not able to complete your order right now. This can happen for a number of reasons, and there may be some things you can do to help.

Why did this happen and what can I do about it?

We take security around our customers' accounts very seriously. This order might have raised one of our security flags that you can clear by filing a Purchase Support Ticket. We'll have someone look into the order on our side, and once we're sure it's really you, we'll be able to get you all set!
If your account was compromised in the past, it may have a past block on it. You can also get in touch with us here, and we'll be happy to get you back on your feet again quickly.
The bank or service that issued this payment method may have blocked this order. You may want to get in touch with the payment provider and make sure the order can go through on their side.
You may want to try a different payment method entirely.
You may also want to try again tomorrow. Sometimes when people order too much, too fast, the billing services may interpret an order as attempted fraud. If this is how you normally order or plan to in the future, you can also get in touch with us here. We can verify it's really you, fix you up for this order, and make sure you don't get blocked in the future.

I am in Brazil and have tried several forms of payment. They all exhibit the same problem.