No consent for credit check

I have recently downloaded my annual credit report and to my surprise found that a credit check has been done by Lewis Stores in August this year without my knowledge or consent. I have never app**** for any credit or even had an account with them, meaning that someone else could have been trying to use my id to get an account. I have emailed the head office about this but nothing has been done. I consider this to be very serious because my identity and credit record is in danger.