Since the latest patch was applied obtaining medals has become next to impossible. Through reading and experimenting this is what has worked for me so far.

You need to capture the valley and not just beat the defenders.

Civony medal post patch

This was a level 6 valley and about the 10th valley I hit and got the medal.

I hit hundreds without conquering the valley and recieved none.

Hopefuly this method will be proved to be solid in the coming days. I will keep the post updated as i learn more and my alliance finds more medals.

Another medal ontained in less than 10 more hits

Civony medal after the big patch

This was a level 9 valley