The Airtel Triple Data offer gives you a gift of 3x the amount of data that you have purchased. For example, if you buy a data plan for N1000 that contains 1.5 GB of data, you will receive 4.5 GB of data and N3000 airtime bonus to call all networks. That's three times the amount of N1000 and 1.5GB data you have purchased. Valid for 90 days for all purchases of data packages under N5000.

To activate the Triple Airtel Data Bid
You must purchase and register a new Airtel SIM card or use an Airtel SIM card that is less than 3 months old.

At present, SmartCONNECT 6.0 is an Airtel standard prepaid bonus package for prepaid customers, offering a 100% bonus or triple the INSTANT bonus for each data plan and an 8x bonus for each bill.

>> You have to recharge your new SIM card for full SIM card activation

>> Then send GET to 141.

You should get a response message like this,

Dear customer, congratulations! You can enjoy 100% DATA BONUS for the next 3 months every day

>> You have to send MIFI to 141.

Then recharge your SIM card with the amount of data you want to buy.

When finished, just buy any data plan that can be purchase with the required airtime amount. Suppose you subscribed for the N1000 worth of Data, you will receive 3x of N1000 worth of Data

Dial * 123 * 1 # for bonus balances, * 123 * 2 # for Voice Package balances or * 140 # for package balances.

Just incase you are not eligible or you want to try out for other networks
Read from source
https://www.cybertechguide.com/2019/09/cheapest-subscription-nigeria