Customer gambling game

Good day, I've been with Zoom fiber and now all of a sudden my router is not working and Zandile from Accelerit send me an email stating I am now with them. I tried reasoning with her I am with Zoom fiber she must just cancel my account with them but now she tells me to first pay cancellation of R543 which I don't have and don't understand how they got to my details. Clearly they *****ing customers from zoom.