Billing account ! Help!

Hello. Until 3 days ago I had 4 workers on hive and one on Ergo mining. I pay $ 0.50 daily. OK. After that I moved the last rig to the Hive pool and I still pay $ 0.50 a day. What is the problem ? I have seen many accounts with many workers costing $ 0. I know several friends who have more than 4 workers and they still cost 0. I also attached pictures.
Thanks !