Group Plan payment update

So I updated the payment method I have for my sim and my sons sim and the payment method was accepted for mine. My son's phone just says awaiting number which he has had for nearly two years with smarty. Tried reboot and removing sim nothing now for 4 days and he can't get access to his account because of code sent to his number is never received. Should I remove him from group plan as its seems a lot of hassle first, but how do I get his original number to be recognised, and he can make his own payment method ?