I wanted to subscribe with Data4m3 *121# with the sum of #3,5000

Hi Atinuke, I think this DataME offers are not constant, but changes from time to time depending on your usage. You will be able to activate double bonus offers.
You will be able to activate any of the offer with any of the steps below:
1. USSD *121#
2. My MTN APP under Quick Access, select MEGA DEAL ZONE (Crack The Egg feature).