Being overcharged for a contract that I have been paying for !

I have had my vodcom contract for the past 24 months with that came endless billing issues, speaking to consultant after consultant even having my issues escalated to management with not one person who knows what they are doing. I have all of my receipts to prove that my account has been paid and never once has my account been in arrears. I get a call today stating that my account has been in arrears since 2022. When I had asked for proof of such there has been nothing sent to me. The consultant was absolutely rude and not even willing to help. Even the managers don't have the slightest clue. My contract was supposed to have come to an end in the month of April 2024 I went through the necessary steps to inform them about such and I will be canceling, they then go onto to tell me that I have not paid for a handset and I still need to pay for it for 2 more months. I asked to speak to a Manager she goes on to tell me that it's true and unfortunately I will have to pay which I could not understand because from the date the contract was taken out I have never not once missed a payment. Now today I get a bill of R2000.00 stating I am in arrears and my bill has is a month behind payment which I can not understand I then ask to speak to a Manager and no one had gotten back to me.. if you ask me vodacom are just ******* looking to make free money of their clients with no proof of such an amount being owed or due ... absolutely disgusted and would not suggest any person to take a contract out with them ! One of the most useless company's to deal with.