Expensive Telephone Charges

I received this SMS: Welcome to Tunisia. To call Singapore, dial +65phone no. Voice @$5/min. SMS S$0.60/sms. Data S$20/MB.

Wow! I called home using Skype! But if I make a mistake and accept an incoming call on my mobile phone, I have to pay this high charge. This is how business make profits - catch the unwary customer!