Billed for international call with blocked service & International day pass time zone issues

ATT software doesn't know how to calculate time zone differences, I was charged for calls/data while overseas with the Day Pass for $10 per 24 hours.

It took at least 3 calls to explain to the operator that Europe at least 8 hours ahead from California and days differ .... after finally explaining that, I was promised a credit, which never made to my statement but new charges for blocked international calls showed up. 

All my lines have blocked international calling. We only use calling cards or Free VOIP services like Skype, Viber and other just in case we don't make $3/min calls.

Somehow I see charges on my statement for international calls, how is that possible?