Food Standards has two entries in this area https://ratings.food.gov.uk/business/1274116/caxton-stores-derby https://ratings.food.gov.uk/business/1526762/go-local-extra-derby and neither mentions Nisa Local
Am not sure if there is really just one Caxton Stores that is a Go Local Extra or if there are two businesses
The Nisa Local facebook page for Caxton Street has not been updated for 5 years https://www.facebook.com/profile.php?id=100067462442942