If you have pre-purchased a data plan and you have lost your home/primary data service, it's likely because your default Cellular Data Plan has been changed to the GigSky eSIM Plan. To set this back you need to do the following;
- Go to Settings -> Cellular
- Tap Cellular Data at the top of the screen
- Select your "Primary" SIM for cellular data.
If you have any further questions, please contact GigSky Support at firstname.lastname@example.org.