SMS's to my number but not my account

I keep getting SMS's that MR MOLOKA JOEL MOL is being handed over because his MTN SP account is in arrears. They also keep phoning me to speak to this person. I don't know how they got my number, or why they are looking for this person from me, because I don't know this person and this cellphone number has been mine for more than 13 years. Please get your fact straight and stop spamming me with other people's stuff!<br> ***