Stop calling or sending messages I don't owe you

I have a problem with this bank, I was used by someone as a reference when borrowing.Now they are busy phoning me looking for him, I have told all the bunch of those recovery guys that I don't have account with them and I don't have their client's phone number but what I don't understand why they have to harass me.They have started sending sms to my phone demanding money.<br> Can you please refrain from this.My phone is my private property and I didn't grant you consent to use it the way you using.I don't have any business with you, Im not going to be your recovery agent now or even in future.<br> <br> My contact numbers and/or any of my personal information must be removed from African Bank database and must never be used by any of your employees, business partner or any person with relationship with you.<br> <br> Should you fail to act on this request I'll have no option but instruct some law expects to assist me on infringement of my legal right as per POPI.