There is a way yeah, just contact support. If the clanleader is absent for more then 30 days, support will relocate the leader role to the most active player with the highest rank.
So if there are 3 normal ranks and only 1 leader rank, the most active of the normal ranked will get promoted by support.
Also works if you need to obtain founder rights from the clan, so that you can kick the previous leader from the clan if you want to.