If you have a zantel gsm line, please dia *775#, kuna menu itatokea, chagua menu 2 ambayo ni "Recharge inquiry", utaingiza namba yako ya modem then utaingiza namba ya voucher. Baada ya few seconds utapata msg ku-confirm kama credit imeingia. For more info please call toll free number from ur Zantel line [15096] or send an email to: <r.tarimu@zantel.co.tz>