I bought an LG KS360 from Vodafone about a year and half ago. It has a Vodafone SIM card on pay-as-you-go. I have been out of the country for eleven months. My phone has been dead and the SIM untopped up for about that amount of time. As soon as I returned, I charged the battery and turned it on. It says "rejected by network". Do I just need to top up my payg credit, or do I need to get a new SIM card?