Back to basics needed - the business was quick to disregard its customer base and chase other customers. Concentrate on core products and services and offer better training to staff.
Young people are cheap to employ but to get better sales you need experience and mature people
Seeing as this was Family built and Family run business for so many years, the family morals have gone completely. If you have or want a family and want to enjoy them don't work for Dunelm!!! Management needs a MASSIVE shake up as well. Disgusting attitudes from some of them!!
You should invest in security in this store. Update the computer systems, cameras, and staff. Find yourself a new manager that doesn't hide from the public and her workers. Why does she allow her close friends positions of power?
Actually go to your stores, read the reviews on your company, and give your management a boot.
Consider that quite a few of the staff who does organise (face) the shop are students, so if possible minimum working hours could be decreased, or even yet just negotiable (although that would require the higher team members to be approachable)