Report Builder - Customer Contacts

Good Morning:

I created a report in report builder that lists customer info.
(address, etc) and all contacts associated with each customer by
joining customer and custcnt on company and custnum. However in
addition to pulling contacts it also pulls the customer's ship to
(s). I added a filter where customer.shiptonum = ' ', but this
eliminates all customers with shipto's contacts, so this doesn't work
either. If anyone has any insight it would be much appreciated it.

Thanks,

Mark Smith