Hello. My name is Michael. I can help you with your question.
The way to accomplish this is to "claim" the business through Google. Once you do, you will have control over the listing and you will be able to change the phone number to the correct one. This is definitely an inconvenience, but it can definitely be corrected with a few steps. Start at the Google "my business" site and set up your account there... it is all free, BTW... just a pain in the rear-end. On the other hand, you only have to do this once. After that, you can use the listing to your benefit.
Once you do that part, there are many ways to do this. You can either go through the steps there if they are different from these, or you can do the following:
It will go through a verification to ensure you are one of the people who can act on behalf of the business. Once that is done and you are the verified owner, you can make whatever changes you need. Let me know if you have any questions along the way.