Horrible service, horrible cancellation terms

I have been with Vumatel under Webafrica for almost 2 years now. I had connection issues almost every month, I never missed a payment and despite being on a month to month plan they are still charging me R999 to cancel their service. They have not even arranged to collect their router and I could possibly incur more charges if there's anything missing from it. Total charges can be up to R2000 just to cancel. They say these are terms and conditions I agreed to but they are not clear about any of this when you are signing up. There's not even a digital or physical contract for me to refer to. I just received a screenshot from their agents about the cancellation terms.