Blue label Connect and Ver-tex solutions

I have a 24 Cell C sim contract with Blue label connect, they are debiting from my account since the beginning of the contract in August 2022 but according to their system I am not paying at all. They have calling me and I always forward the proof of payment but they don't find it from the email they provided. They ended up handing over my account to their collectors (Ver-tex Solutions) of which I also explained to them and forwarded my bank statement from August 2022 to May 2024 proving that I owe nobody. Unfortunately Ver-tex solutions is not interested in hearing my story they only want the money Blue Label connect claim that I am overdue with. I have tried sending emails to both parties and even went on to share my bank statement on WhatsApp (Ver-tex solutions) but they can explain to blue label Connect that they are debiting from my account monthly and I have never skip any month since the beginning of the contract even my Sim is no longer connected. Now my biggest challenge this is impacting negatively on my credit score... Any assistance my fellow South African