Hi!
If your phone does not respond to your case, we recommend that you check that you have the latest update. Which you can do via settings > Software update > Update now. Should you have the latest version and it is still the same problem, we recommend that you go to Settings > Advanced features > Accessories. See here if your case appears as an alternative. If it doesn't, your phone doesn't recognize the case.
Which then we recommend that you test the case on another phone or try backing up the phone and then factory reset it to rule out software errors. This is to rule out if the fault lies with the phone or if it is your case.
We hope this is of help.
/Daniel
