You have been doing your best and besieged thousands of Castles last week, right? Then you recalled troops and continued besieging Castles; however, you have not received any new Ranking points. Here's a thing: you receive 100 points in the Weekly Siege Ranking each time when you besiege a Castle.
The Weekly Ranking is updated every Monday at 7:00 AM UTC for all players around the world (even if you play from the North Pole). At that time, all Siege points earned last week are reset to 0. Hence, when you start recalling troops from the besieged Castles, you get -100 Siege points each time.
How do I fix this and start receiving points again?
There are 2 solutions:
1. Having recalled all your troops from the besieged Castles, first, you need to besiege some new Castles and earn new Siege points to reach 0 value. After that, all further Sieges will be bringing you points for the current Weekly Ranking.
2. An easier way is to wait until next Monday when your current negative value will be reset to 0 automatically.