When I try to start whats app, They sent me 6 digit pin no at my mobile number. didn't receive yet. My vodafone number is old. I have been using since 2013. The number is ok. But when ever I put the nano sim the problem arise. Even I tried to send sms from other number. But still not getting message. What happen with me new phone?
You cut the SIM by yourself to make it a nano SIM? If it's not a signal issue that can easily be refreshed by a simple phone restart then I'm afraid you may have accidentally damaged the SIM. Take it to one of your carriers outlets to get a new SIM card.