How can I block my sister's phone number, the phone was stolen

Stole phone Sim number 08038920691 I have been trying to block it but all to know aveil because she doesn't know when she registered the SIM she can't remember

Pls I want my sister's phone number to be blocked because it was stolen yesterday evening

Please my sim is blocked and I have an emergency call please I need a puk number to retrieve it my phone number is 0702 632 0305

My phone was stolen 08104289305 please block it