1. When you see the MTN Zone on your phone at about 60, 70, 80, 90%, then dial: *135*1# and Send/Ok
2. After that immediately dial: *135*7# and Send/Ok. Please, if don’t type this second one, you will not be able to receive calls.
3. When you want to make calls, it will show you the percentage discount of the call. Assuming you want to call another MTN line: 0703.2733047. The network will show something like 50% or 90%. What it means is that you will be given a discount of 50% or 90% on the call you want to make. If you like the discount, just place your call. With this measure and feature, you can make 5minutes call with N20 only.
4. If you want to migrate back to the package you were using before, do dial: *135*9# and Send/Ok