From a tweet on GTbank official tweeter page, it says
Give airtime to your loved ones in the 12 days of 737 Promo!!! Get back N737 when you recharge N737 airtime for your friends and family.
Now from the tweet if you recharge any line with your GTbank registered phone number, you will get extra N737 worth of airtime and this airtime can be used to make calls and browse.
How Do I Recharge With The GTbank USD Code
All you need to do is, juts dial *737# then follow as directed on your screen then after carefully following the prompt and successfully recharging the desired line, your free airtime will be send to your main line.
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