Trying to use iPhone 4s from Australia in Canada

[Oatmeal]

First off, let me say the details are sketchy, but here goes...

iPhone 4s from Australia on Telstra, was supposedly unlocked through Telstra, but a Bell sim card does not work in it. The users contacted Apple, who could not get it to work; Bell said the sim was faulty and that another sim would have to be purchased.

What are the first steps I should take to figure out what the problem is?
Can I assume the phone is still locked?
What happens if I attempt to unlock it too many times?

If anyone could point me in the right direction, it would be much appreciated. By the way, I use an Android phone, so I have no clue about unlocking iPhones.

Thanks,
Oatmeal

[jerryhung]

Try/borrow a different Micro SIM, or just get a hopefully free replacement from Bell store, or visit Apple store ask them to try

If that works, it's unlocked; if not, it's locked and you're SOL