Have you verified the address in https://i7lp.integral7.com/durango/do/login?ownername=sun&channel=sun&basechannel=prometric under Personal Information --> Addresses.
If the address is correct then the following is mentioned in the FAQ. I have not received my Sun Certificate/Welcome Kit. What should I do? # First confirm that you have completed all Certification requirements to be awarded the Welcome kit. To confirm this select Certification Progress to view your Certification status. If you have met the requirements you can view the status of your kit fulfillment by selecting History. In the History-View drop down menu, select Fulfillment. If you do not see information for your kit you can submit a new Incident Request or you can send an email to: firstname.lastname@example.org.