A Google Maps Help thread has continued reports of the SMS based Google Local Business Center verification not working correctly.
When someone receives an SMS pin and enters it in the Google Local Business Center, they are hit with an "Incomplete" response. Google Maps Guide Linda confirmed the issue in the thread and said:
Is this occurring only for SMS request for PIN? Please let me know if this is what you're experiencing.
The work around this is to request PIN by mail which may take 1-2 weeks. There should be a pin box where you can enter the PIN. Once you do this your listing should appear on Maps within 24 hours.
If you have this issue, please post it here. This is a known issue and we are working to resolve it.
Forum discussion at Google Maps Help.