repeatedly sending me another FNB clients personal account statements/info

FNB, every month without fail sends me a complete stranger's credit card and savings account statements. This amounts to FNB sending the account number, personal address, opening and closing balances, details of all purchases and whatever other information you would hope your bank would keep private, to the wrong person. I have repeatedly contacted FNB in this regard and asked them to stop but still it continues. I delete these mails as soon as they arrive but cannot help wondering whether they have not been just as negligent with my own account statements. FNB get your act together. You are careless and grossly *********** in this regard!