I am sorry you had issues but I think better communication on your part would have helped your case immensely.

I don't know anyone who can bill any amount they want to and expect it to be paid.  

$45 is the going rate here in Birmingham for a current owner search. I know there is no requirement that a LLC is restricted to only purchase commercial property, so unless the client pulls the taxes for you, they wont know it's commercial when they send the order.

De rigeur I contact my client with the new information and they decide whether they even still want the search, and what our rate will be. 

I have worked with SLT in the past (but am not currently) and have never had a problem getting paid my full amount and on time.