Vodacon and MBD inc

Beginnint of 2019 i was told by Vodacom that I owe the money for the contract they say i took. I explained to them that I Know nothing about the contract and they said i must bring my ID copy and an affidavity to prove that im not the one who took the contract. I submitted everything as requested, they even showed me the **** ID used in the system and the signature was not mine. I thought the matter was resolved but NO! Later my cace was handed over to MBD inc. I explained the same thing to them and they asked the same documents as Vodacom. I emailed them 3 times faxed them now they are threatening me. Who is not doing their job here coz this not right.. I DONT HAVE A CONTRACT WITH VODACOM