I have an unlocked HTC Desire S phone (brought with me from the UK, just moved to Canada) but when I put a Canadian sim in it it doesn't work. I've tried having it unlocked and both my own efforts and the company to took it to couldn't unlock it - I was not prompted for an unlock code. I've tried sims from various networks and none work. I want to be able to use this phone with Koodo, and it should work, but nothing will make it accept the sim card! Any ideas?