Changing regions

I am trying to change regions (recently moved from Argentina to Poland) because I can’t use my current card with my region being Latin America (I don’t know why). Basically my account was created before Blizzard was purchased by Activision.

Now I can’t even buy a subscription to WoW. I’ve sent them the documentation but they say ‘After extensive research I have found that it is not possible to change your country because the information has not been verified and we count on your understanding and support in this response.’ I really don’t know what else to do. I’ve sent my passport, my internet bill from Poland, even my landlord agreement to no avail.

What should I do?