I don't know about months, but it should increase too. There was a user above who used multiple subscriptions of same package, ask him.
The offer is supposed to end, as many people misuse it. i am on warid now. I just took two warid speed tests and they are much slower than zong, due to this offer.
Warid LTE speed test, outdoor with 3 bars signals strength.
Check out my Ookla Speedtest result. What's your speed? http://www.speedtest.net/my-result/a/1399711004
Actually, H+ can offer speed upto 42 mbps, so these LTE speeds are just a joke. Lte is supposed to be 42+ mbps speed.
But i like LTE, as it drains less battery as compared to 3G in normal internet use and phone doesn't get hot too.
@chaudhary9
Update, check signals using sim, the coverage map is just an idea.