Faulty cellphone number

I am in need of some assistance. I will detail my problem below.<br> My Uncle purchased a new simcard for his use when he visits the country. I believe this was purchased on 26 November 2014. When he left in January he gave me the card to keep and use while he is out of the country.<br> I have used the card a couple of times since he has left both sms and calling from the number. When I came to use it again last week the number was not working properly. I could send sms's and receive sms's. I couldn't make or receive any calls. I tried to load more airtime but the airetime would not go through. I got an sms saying number invalid. I have tried again today but the phone doesn't ring. It just goes to voicemail. I can send and receive sms's.<br> I don't understand what the problem is. I have tried inserting the card in different phones but problem stays the same.<br> Could somebody please assist me. The number I am quering is ***.<br> I think my Uncle registered the card in his name - but used my address. His name is Charles Marshall.<br> Please assist me to solve this problem.