how do I merge duplicate contacts?

Situation is:

1.  I had a list of contacts in Zoho CRM.

2.  I purchased the paid version because it has Google Contacts and Calendar Sync.

3.  When I did a Sync from Google Contacts to Zoho it created a whole bunch of duplicates ...

Also it imported everyone!   Not just the contacts from the google contacts 'group' I had selected.

The sync is set to daily.  I don't want a whole new list of contacts every day.

Joel