Trying to ***** me with mbd collectors

This company is starting to annoy me now.i dont owe them any cent or received any cent from them.but now they busy sending mbd colletors to me saying i owe them R22000.i dont know they trying to ***** me or damage my credit record.so, people just be aware and dont just put your details anywhere like capfin websites.can please any one help me to report this capfin and mbd to relevant authorities.