AMP Security Un authorized credit check American Fork Utah

This company came to my house and asked me for some info so they could verify if in fact I was the owner of the house. Well they went ahead and did what they calleda "soft credit check" without me signing the authorization form. Then they tried to minimized the fact of the violation by telling me it wouldn't show on my credit report. Now today My credit monitoring system sends me a warnig for some credi file activity and sure enough, AMP Security did in fact an inquiry on me. 

I called the company and I was told that in order for them to correct the situation, I had to write a letter notifying them as to do so.  in other words, they violate the law, they make the illegal inquiry and I am the one required to write a letter.