First of all there is no such thing as creating White hat backlinks. Any backlink you create in order to improve your rankings is black hat, period. The fact that this guy is claiming that he build white hat links means that he either have no idea what he is doing or he is a liar.
Second 75 links for a week? There is pretty decent chance that your website may improve its ranking for a bit and then get hammered by Google (meaning penalized and out of the index completely) for unnatural links.Also those links are most likely 1. Shitty PBNs, 2. Spam comments, 3. spam forum profile links. Complete waste of time.
Third - you should ask here for advices what to do with your website SEO before actually hiring some half brain idiot to destroy it..