Yelp Billing me for an advertising campaign that was not authorized or wanted. San Francisco California

Yelp is asking for money for an advertising campaign they ran for my boyfriend's business. We had no knowledge of this campaign and did not authorized it in any way, shape, or form. They claim they spoke to me on my phone number on a certain day but going back to my call log on my cell phone for that day there were only two calls and neither one was from Yelp.

I have spoken with them and have gotten no where. They said they would "review" the recorded conversation and get back to me. They also said they would email the agreement paperwork that was supposedly ok'd by us, but they never did, because we never ok'd anything, and no one ever got back to us.

Now they are sending threatening emails to ruin our credit!