Q: This apps are not free anymore?

Thanks for replying. I have already tried that, but it does not show those apps on my "purchased apps" or on the "not on this iPad" sections. I already logged out and logged back in to iCloud and App Store, also restarted the iPad and nothing seems to work. It is still asking me to purchase them.

Yes, I'm using the same Apple ID (where I download the iWork's apps the first time) and I purchased my iPad on March 2014, and I also read the article, but I did not find it very helpful.   And I've also spent hours looking for a solution on the Internet and saw many people having the same issue but none of them have found any way to solve it. I really don't know what else to do.

Thanks, I'll make sure to contact them.