Although currently it is a bit misleading since they seemed mixed up on the Task page, there is an easy way to spot the difference between a TASK and a CONTRACT:
A Task is a downloadable- or browser PC game. Tasks will always start by clicking the "Play for Free" button on it's page and need to be completed by clicking "Complete this Task" and uploading your screenshot as proof.
If your task will get rejected you can seek out Gamehag support and try to get your issue solved.
A Contract among other things posted on the "Wall-of-..."pages is often a mobile game for iOS and Android.
Contracts should reward automatically after you completed the requirements.
Sadly many users report that they are not getting credited on certain contracts.
The rewards are given by 3rd parties at their discretion and Gamehag holds no influence on those.
That is also why Gamehag support cannot help you if you didn't receive any credit, and so you should seek out 3rd party support.
FINDING THE RIGHT KIND OF SUPPORT FOR YOUR ISSUES:
https://gamehag.com/forum/t/20457-not-getting-your-sg-heres-the-correct-way-to-get-support
THANK YOU BRO.
in 3 steps
Choose the game that interests you and play itfor free.
Every game has some quests for which you will receive Soul Gems.
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
You know that on Gamehag you can get real rewards for free, right? Join us, complete walkthrough and get your chest!
Since people ask and complain often about this topic, here is some information about Tasks and Contracts: