Despite using only a single worker, I have noticed that I am being charged $0.30 daily
did you have 3 rigs online in a 24hr period? if not, you can email [email protected] or chat on hiveon.com with support and they will look into it.
if you did have 3 or more rigs online in 24 hours make sure to disable paid features in the billing tab if you went back to a single rig.