The steps below show how you can buy 1.2G data bundle. Telikom PNG offers free data bundles if you subscribe to same plan twice. So in order to get 1.2G for just for only K18, follow the steps here.
1. Purchase a K20 Raitprepaid Card.
2. Top it up on your phone or modern (for modem, dial 1255 on any landline and follow voice prompt to recharge your modem)
3. Purchase data 400 megabyte twice and Telikom will give your another 400 megabytes free. Dial 1255 > Follow Voice promt> enter 4 > enter 3
So in total, you will have . 400M + 400M + 400M =1200M = 1.2G which will expire after 14 days.
You can do this for other plans. Simply study the screen shot above.