Mbd and virgin active

Please help with MBD calling me regarding my Virgin active account I understand I owed and I have made the full payment as per the letter they sent . the letter advised the amount due was R1434 I paid it in full but this company keeps calling stating I still owe funds. They keep calling with a number listed as ****. This is ******ion and I will be reporting this company. I have made payment I don’t see a reason for this harassment.