It's been more than 2 weeks and still waiting for verification postcard?
If you have requested the card and waited at least two weeks and it hasn't come, you need to contact support and they will assist you with getting verified.
To contact support:
To get in touch with Google My Business Support ou need to:
1- log into your Google my business dashboard http://www.google.com/mybusiness
2- select support from upper left hamburger menu
3- a help screen will appear to the right
4- It used to be just a scroll down to contact us under Contact Us
5- Scroll down and select Need More Help
6- Select the specific problem - in your case Verification
7- Select I requested a postcard more than 14 days ago
8- Scroll to the bottom of the page and choose most appropriate contact method for you (some are not always available)
Hopefully there will be a contact choice available to you