How do i contact jem computer systems? Last Name: Email Address: Organisation: Contact Number: Subject: Enquiry: Head Office JEM Computer Systems Unit 32, 9 Salisbury Road Castle Hill NSW 2154 02 8860 7575 02 8860 7515 (fax)Where is the head office of jem? Head Office JEM Computer Systems Unit 32, 9 Salisbury Road Castle Hill NSW 2154 02 8860 7575 02 8860 7515 (fax) Service & Support 1300 JEM COM 02 8860 7500 [email protected] Postal AddressHow do i contact gem outside of new zealand? Outside New Zealand call +64 800 500 505 Mon to Fri: 10:30am - 6:30pm Weekends: ClosedLive chat with us from 8:00am - 6:30pm Monday to Friday Gem Visa Live Chat