If you use N100 Credit, You get N500 Bonus. If you Exhaust N200 you get N1000. You need to first dial *507# and make sure you receive confirmation sms to enjoy the bonus as you used N100 recharge card.
=> Now to get N500 with N2 make sure you are on MTN Zone [Dial *135*1# to migrate to MTN Zone] and make sure that you have minimum of #2 on your phone.
Wake up any time after 12 O’clock at mid night and call any number [MTN] Use the N2 and you we be given a N500 Bonus that you can use to call all MTN Numbers through out that day.