you can now get 500mb data with N25 only to browsing and download from 00:00am to 4:00am midnight everyday with your MTN line. So if you have more than one MTN sim card you can be able to have more than 500mb each night. This night browsing works on MTN Ipulse only. To activate it you have to migrate to MTN Ipulse by dialing *460#

Make sure you are on MTN Ipulse tariff plan make sure you have N25 credit in your sim card then text NIGHT to131Your N25. that's all.... enjoy

source : http://www.nairabit.com/2016/05/get-500mb-for-n25-mtn-cheapest-data-plan.html?m=0

Omo see jollyment o

So why didn't it work for me? I sent the code multiple times and mtn replied saying they're processing my request. For two days now, nothing.

Anyone that could me with a group on whatsapp named "android forum" this my number if you can help 08137409829

@ charix, I think its the network in your area..you can call their customer Care

wilnaira:
@ charix, I think its the network in your area..you can call their customer Care

It's not the network. MTN put a funny protocol to it. This is how I fixed my situation.

Finally gotten it to work.
For users already on pulse, mtn has created a new pulse one has to re-register into. Keep dialing *406# repeatedly till you get a message saying you can now activate the overnight free browsing option. Persistence helped me here as frustration was taking a hold of me.

you are right....it happen to my friend but he told me he kept sending *123*2*3# until he got a positive response

and it doesn't affect ur mb if u are already in a data plan