FNB threatens non client for payments

I got an sms from FNB stating that I owe them R3471. They threatened me with a debt collector and was all up in arms. Well cool FNB I would have gladly paid back your make believe money IF I WAS A CLIENT AT YOUR BANK!!!! I do not, I repeat not bank with you and I will make sure I will never bank with you. I need from the following. An apology. And a statement where you admit fault. <br> <br> Just to be clear again. I cannot owe you money, because I do not bank with you. I do not know of such an amount I owe you. I recommend you rectify this ;)<br> <br> Thank you