Switch phone off for 24 hours

Further to "no signal": I received a phone call on Monday from a man called Fergi. He asked me to change the network selection to Vodacom, which I did. I also tested the Vodacom sim card in someone else's phone. It worked perfectly. On Tuesday he followed up in order to find out if I now have a signal om my phone. No, I still do not. He requested me switch off the phone and remove sim card for 24 hours, which will be today being Wednesday at 14h00. I am waiting in anticipation!