That doesn't sound like a SD card.
A SD card is for "External" phone storage space. A SIM card, however, is how you would connect to your carriers/service providers network.
If you are referring to a SD card, it has nothing to do with access to any network and would have no reason/ability to connect to the carrier/service provider.
If this is a SIM card that isn't working correctly, then you need to contact the carrier/service provider and get them to help your resolve the issue. You may need a different SIM or that phone may not even work on their network. Only they would know for sure.