You could try ordering a replacement sim to see if that helps so if this link doesn't work:
https://www.sky.com/productsettings/mobile/sim/x/replacement-sim
If you can't then will have to contact Sky, perhaps via social media as there are links at bottom to their sites.
__________________________________________________________________________________________
If someone has helped you then please click on the LIKES button in their post.
If you need help please provide as much information as you can
