Stolen phone, sim still active as phone rings

RobinBu_2408526 You can report the sim as stolen and it will be blocked. You will then be sent a replacement sim that will need to be activated in order to unblock the account.

https://help.smarty.co.uk/en/articles/1215834-what-to-do-if-your-sim-card-gets-lost-or-stolen?_gl=1*sehm50*_ga*MTk0NzA3Njc5OS4xNzA3NzM5MDk4*_ga_D8LNLN41LX*MTcwNzkwOTI3NS4xNC4xLjE3MDc5MDkzOTkuMC4wLjA.