MTN open *****ulent accounts without the necessary FICA docs

On the 7th of Feb 2024 I notice that MTN tried taking a debit order for over R3000 from my bank account. My normal debit order is about R428. I contacted MTN who stated that I had purchased 2 new contracts and it incurred charges of R2300. I informed the consultant from MTN that I had not purchased any new contracts and had not changed anything on my existing contract. I was then told that I need to supply proof I did not. I cannot take off work as I don't get paid if I am not at work and have to give 2 weeks notice to take time off. It is not my responsibility to prove innocence. MTN must tell me hom they opened contracts without FICA docs and my signature and look at camera footage to see who opened the contracts. I refuse to lose money because of MTN's incompetence.