I am also a native speaker and I can garantee you that we do use that expression. Only, there is a typo in Stilius' translation: it's 'gelukkige verjaardag' and not 'gelukkig verjaardag'.
'Hartelijk gefeliciteerd met je verjaardag' is also correct, but is less common in Belgium (it sounds a little more formal; we would write it on a birthday card, but we would not say it).
Natonaty is Dutch, I am Belgian, that is probably what causes this conflict of opinion. Conclusion: choose the answer according to your target audience.

en
'Gelukkige verjaardag'

are both correct, even though 'gelukkige verjaardag' is not commonly used in The Netherlands'.

In Belgium both expressions are used.

I, therefore, agree with King Darling:)