I've just bought a used but unlocked Sagem MyX2-2 to replace my MyX2 model which has a damaged casing (but still works). The SIM card is a Vodafone PAYG and I thought it was a simple matter of sticking the SIM in the new phone and Bob's yer uncle! When I do this I get a 'sim locked' message. I didn't get a user guide with the new phone so am unsure what I need to do now. How can I get the new phone working with the Vodafone SIM card?