Thumbtack Fraudulent Leads Southern California San Francisco California

I've been using thumbtack for years. Now, I'm starting to suspect fraudulant leads. For every legitimate lead you recieve (although you may not win); there's 10 bogus leads. Lately, they (fake lead) have been writting back stating "Going a Different route". I have had over 20 leads in the past 10 days all with the generic "Going a different route" response that seems highly suspicious to me.

Also, if you look at the leads name...they more than likely always end with the letter "S" (for example, Maria S. David S etc..) or double constanants (Ana A., Coleen C. etc.) So if they are going a diiferent route. They should automatically be refunded. Not to mention the "hundreds" of other leads that we haven't heard back from. We've even lowered our rates 50% to see if theses leads are real and NO LUCK. How do we proceed with filing a class action lawsuit?

Please Help.

Tony