I'm overseas I only use my cell when connected to WiFi.
I've uninstalled all unnecessary apps, optimized my battery usage, set my phone to turn off and on during the night.
My data is off.
Why am I still roaming and being charged exorbitant charges?
Roaming fees can only be charged when a Fido SIM card is connected to a network in a different country. In this case, can you clarify what kind of usage you're using on the phone while abroad?
Is your data roaming/mobile data disabled in the phone's settings?