Using my phone in turkey

[#1]

Currently on holiday in turkey and within 1 hour of landing my phone had used £30 of chargeable data, exceeding my cap and leaving me with no internet.
I understand you charge abroad but this seems excessive.
Should I have a setting turned on to avoid these costs or even reduce them?

[#2]

If you're not going to a roam like home country, you should switch roaming off on your phone.

[#3]

A word of warning 

If you are going to Southern Cyprus who are part of the EU so you can use your phone "Like at Home"

If you go near the border with Northern Cyprus or even into Nicosia you may connect to a Turkish transmitter and be charged