Don't worry, the delay is normal. The kit is always indicated as "mailed" about a week after you take the exam, but you may not actually receive it for another few more weeks. If you still haven't gotten it after a month, you can contact Prometric as indicated in
Sun's certification FAQ:
"If you still have not received your certificate after the one month waiting period and your address is correct in the CertManager database, please send an email message to
suncert@prometric.com. Please include your Prometric Student ID number in your message."