If you go to claim your business on Google My Business and someone else has already claimed it, follow these instructions to request admin rights and/or reclaim it. If you are in a larger organization, we recommend you request admin rights first as it may be a colleague who has claimed the business.
Step 1: Go to Google My Business: http://www.google.ca/business/. Click the “Get on Google” button.
Step 2: Search for your company name. Select it.
Step 3: Request Admin rights.
If you do not get a response from the current admin, you can contact Google Support. Note, you need to login to your Google Account before you click on “let us know” so you see the form that pops up.
Link: https://support.google.com/business/answer/4566671?hl=en&ref_topic=4596754
Google usually responds within one to two weeks.