MTN IS A ****!

I have a 24 months contract with MTN since December 2021 all was well until the beginning of this year. January I got extra R1700 of Usage charges on my Bill that I don't know anything about, I only purchased data for R40 that month. I tried calling to get clarity, and their consultant said they will investigate and get back to me, that was 3 weeks ago, even now there is no feedback. This month I received another bill of extra R1800 usage charges again, when I call their customer service the option for speaking to a consultant does not work. I JUST WANT TO CANCEL MY CONTRACT WITH THIS ******* .