Method 1 (The Hard Way):

==> Send music to 5900 to get free 150mb
==> After You have exhausted your 150mb.. You must have N0:00
==> Text d to 5900, And another 150MB will be given to you. After getting your reply, You can Check your data balance by dialing *559*2# Now connect again.
==> After exhausting the 150mb given to you again, Send Cancel7d to 5900, Then wait for the reply then send D again to 5900. Then check your bal again when they reply you.
==> And thats how you can keep on renewing the 150mb over and over again. I know this procedure can be a bit stressful that's the reason I posted another method below which is very much easier.

Method 2 (The Simple Way).

==> Download Sms Scheduler
==> Launch the app
==> Click on schedule sms
==> Type 5900 in the Phone number field
==> Type Cancel7D in the message box
==> Confirm your date and time
==> Choose your sms sending interval (the time interval you think you can finish 150mb) I used 30mins in mine Save that.
==> Go back to the app and create another entry, And extend the time by a minute.
==> Type 5900 in the Phone number field, Type D in the message box, Confirm the date and save the sending interval to the interval you saved the first one.
==> After completing the steps above, You can then setup your psiphon or simpleserver with the

procedure below.

Psiphon Settings:
==> Open your phone settings > Go to more > Go to mobile network > Go to Access Point Names > Select Mtn, Then create new APN and configure as shown below:
==> Apn type: default
==> Apn: web.gprs.mtnnigeria.net
==> Proxy: 127.0.0.1
==> Port: 8080
Then Launch Psiphon Handler On the handler menu:
==> Proxy type: real host
==> Proxy server: Musicplus.mtnonline.com
==> Real Proxy type: inject
==> Real Proxy server: (leave it blank)
==> Select save and click on "tunnel whole device".
Click on the option tab
==> Region: Japan
==> Select more option, And check "Connect through an HTTP" then select "Use the following settings:" then configure as.
==> Host address 10.199.212.2
==> Port 8080

Save and Connect.

Simple Server Configuration:
Open your phone settings > more > mobile network > access point names > Mtn
Create New APN and configure as shown below:
==> Apn type: default
==> Apn: web.gprs.mtnnigeria.net
==> Proxy: 127.0.0.1
==> Port: 8080

Download latest Simple Android Server and set up as shown below:
==> Click General Settings > Proxy host: 10.199.212.2
==> Proxy port: 8080
==> Injection query/url: http://musicplus.mtnonline.com
==> Injection host: musicplus.mtnonline.com
==> Connection Timeout: 10
==> Injection line: press enter 4 times
==> Log level: debug
==> Buffer size: 8092
Then go to Local Server Settings, tick Use Global Proxy Save and Connect Simple Server by drawing the switch.