Blacklisted phone by another service provider

Unable to make any calls from my phone and after several calls to the customer service centre, I was forced to take the VODACOM CONTRACT PHONE in for repairs. At the repair centre, after standing in line for 1 hour 23 minutes, I was told there is nothing wrong with the phone it has been blacklisted. So I am given the nr ********** to phone. Upon calling this nr and speaking to Gugu I wanted to know as to why the phone is blocked as this was not done by myself. She resolves by saying she will get her supervisor Refilwe Mokoko to phone me. She advises that they have not been able to pick up any calls or requests or emails as to the phone being blacklisted. she will get back to me. So I wait. I receive a call again to advise me that MTN had blacklisted my phone! WHAT????? how does another service provider get it right to blacklist a VODACOM contract phone of a customer that has used only a VODACOM sim card in the phone from the day the phone was collected for use. No response but I am promised a call back.........YES RIGHT! still awaiting the call back and the interim VODACOM is smiling when they take my debit order and I am without a phone that I am paying for ....TOTAL incompetence really! Perhaps if my 7 contracts suddenly receive a "SORRY NO FUNDS" return when trying to put the debit order through I might get some help as the only time it seems is when you mess with their income that they are willing to assist!