Unauthorized credit check

I have not still received any solid reason as to why did FNB run a credit check without my knowledge and I was not applying for any loan but I was just opening an account with them and that messed up and dropped my credit score with 10 point and I am still waiting on them with the solid reason as to why they ran a credit check, the account was opened by Tebalelo Mahlaba who never advised anything about the credit check. I am soo disappointed and now I don't even trust FNB with my information.