I always double check to make sure that the charging is free for the first few hours. If it isn't free, I look up the rate. It should not be more than $0.12/kWh, if it is more, I'll skip.
Sat. we took our first road trip in my new 2017 Volt. Drove up to Santa Barbara, about 54 miles one way. Found a charging station in public parking area, a ChargePoint station. The display simply stated $2/session.....nothing else. Plugged in and enjoyed our day.
Later after we got home I received a notification from ChargePoint that the total bill was $4.19 for the charging session. Not bad at all. Except, the station said $2/session. Sent an email to ChargePoint asking about this. The following day (Sunday) I received a response stating the station owner charges $2/session AND for the total electric used, thus $4.19
However, due to the confusion, ChargePoint refunded the entire $4.19 back to my account. I thought this was darn good service and a pleasant surprise.