That's what I was thinking: it's an overly aggressive attempt at blocking the n-word.
Tried a payment with the word "Nigeria" in it and that went through successfully.
Tried a payment with the word "Nigeria" in it and that went through successfully.
I mean I still see no reason why a transaction shouldn't go through even if it had the word spelled properly. Black people don't have a problem using it (deservedly so!) and I there are contexts where it is somewhat acceptable to use it if only to refer to (for instance) a racist character in a novel.