Let's be honest about deletion
The first thing to understand about negative reviews is the thing nobody wants to hear: you generally cannot get a real one removed. If a genuine customer had a genuine bad experience and wrote a truthful review, Google and Yelp will not take it down just because it hurts. That's by design — if businesses could delete criticism, reviews would be worthless.
Any service promising to "delete negative reviews" for a fee is either exploiting narrow policy loopholes, using tactics that can get you penalized, or simply lying. Negative review mitigation is the honest alternative. It doesn't make bad reviews disappear — it makes them matter less, through methods that are legitimate, durable, and actually work.