Fibre account issue

I transferred from Greencom to Cell C, not out of choice. Greencom sold their base to Cell. Since this transfer, I ended up with somebody elses ID number on my account. I believe that this also happened to over 1000 other Greencom subscribers, are they still sitting with the same issue all these years later. I have been trying to rectify this since 2018, still to no avail. I have been cut off as I cannot access my statement, as you need to input your ID number. I even went into their offices and they took a copy of my ID there. I have logged numerous calls, the last time being on the 15th of March Ticket # [CF187049]. I called last week and asked a Supervisor to call me as this is unacceptable, still no call. I could essentially just walk away and they will sue the other person who's ID number appears on my account. I am so tired of calling and being asked for my ID number which does not help to call up my details. What does it take to get this rectified? I cannot open my statements and then get emails from your collections department on the outstanding balance. I don't know when they change fees I pay what I am told to and if then changes, none the wiser. How difficult it is to rectify the ID number on my account.???