Unauthorized debit and access to my bank card

My complaint is, is that Rain informed me that it is a month-to-month contract. Should I stop paying, it means that my network will be cut off, which has happened, and if I want to take up the offer again, I need to just start paying again for it to be activated. I've done so, and for two months, I've been told I'm in arrears when I'm not because I stopped the Wi-Fi as I have a new service provider. I am, however, being told I am two months in arrears and every time I transfer funds to that card that is linked to Rain, they attempt to withdraw funds and they deduct small amounts every time. When I have requested to have this cancelled via WhatsApp in last week because later I've then been told I need to send an email. I don't understand why as I've been informed from the beginning, if I do not pay, it will not work. I assume and expect it to happen. However, I am having the issue now with my bank card being debited from Rain. I need to have it cancelled completely and never, ever renewed again. Thank you.