Open link http://ml.unipin.com/
Input your user ID and zone ID ( can be found in game profile)
Choose the desired denomination amount.
Select SMS & Mobile as your payment channel and choose Digi below the SMS & Mobile section.
Input your phone number and press the "Confirm" button.
Complete your payment by enter the TAC number received by your phone.
Your transaction is processing and the item will send to you after payment successful.