Cell C deactivated my SIM cards and are requesting my banking details over a public email

I am currently experiencing a bad customer service from this provider, after I complaint about them debit my account of incorrect dates, they have been sending me emails communication that I should send my banking details without even calling me and making arrangements how can one send banking details to a stranger.

My services has been cut off without my knowledge because m told my Is in arrears, therefore nobody communicated with me ever since, when I complaint on Hello Peter I have been told by email that my account is outstanding I should make arrangements and knowing exactly that all my SIM cards are deactivated. How can you treat your customers like this? I fail to understand. When I got my first email I did sent to them now I am getting multiple emails asking same thing and I am not being helped. Nobody offered to decrease my installments or offered me a holiday payment in this covid situation instead Interest are being added without communication. This company sucks