Does a credit bureau have to investigate unauthorized inquiries?

I recently pulled my credit reports and found some inquiries that I didn't authorize on my report. They were stores and credit cards so they were effecting my credit score. I wrote to the credit burea's the same way I had a couple years ago when i saw that my student loan had a late payment when its never late, at that time the bureau's investigated and fixed it. This time with the inquiries, Transunion investigated them and has removed all the ones that wern't authorized. But Experian and Equifax sent me back letters saying they didn't investigate unquiries and that I could contact the bussiness's that put the inquiries on to see about removing them, however my authorization isnt always needed to have an inqury. I have attempted to contact the company's directly but two didn't respond and one just said there was an application filled out online and when I wrote back saying i never apply online, I recieved no responce. Any Advise on were to go from here?