Phone verification broken on Local Business Center; no mail option

I work for a local grocery chain with 18 separate physical locations. I'm trying to add hours, photos, contact information, etc. for each one on Google Local Business Center.

So far:

- one entry has been verified and is up and running
- I was able to get a PIN via phone for a second entry, but that PIN was "invalid" upon entry
- every other listing gave me a "...call was unsuccessful" error when I tried verifying via phone last week, even though I know the numbers are valid

It seems as though the standard response on the Google Help Center is "use mail verification" if the phone option doesn't work. Well, ten of the 18 locations do not give me a mail option for verification.

I've posted on the Help Center @ Google, with zero response. Please, someone, turn the mail option on for all of my listings and turn the phone activation back on, if it was shut off somehow.