Basically, this is how it works:
If your account uses the UK eShop for example, and you're mainly using that, but switch to another eshop that requires switching the region of your account to another country in order to access it, you will not receive any kind of support for said purchase. Nintendo UK support can't help you because it's not a UK purchase. Nintendo South Africa (sike), had they had their own legit support jurisdiction, would not be able to support you on your purchase either, as you were not using your own regions eShop for the purchase.