Hi azeemusman.mca@gmail.com . For changing the country code globally you need to disable the Enabled option for 802.11a and 802.11b/g in WLC global parameters. For individual APs just disable it per AP basis and change the country code.
Did you restart the PI before doing a restore, sometimes a restart resolves the DB restoration errors? If this also doesn't resolve your issues your DB must have been corrupted. You will have to reimage your PI and then restore the backup.