Demand an end to Yelp's blackmail

As a business owner that has been awarded The Best of Howard County 3 years in a row, Yelp has tried to ruin my business by listing all negative reviews. I have purposely asked patients to write wonderful reviews and they are only posted for MAYBE 24 hours then they are taken down.this has to stop.! Yelp does NOT verify the stories; 2 of the comments are not even my office, they belong to an office with the same name in North Carolina.
They blackmail you by saying if you advertise with them that they will protect you from these types of reviews, well I don't have $700 a month to do this; I'm a small business.
Please post this as I am sure many other businesses have had this issue as well.