POOR AND BAD SERVICE

I have not used my data for the past two months (Jan and Feb 2021) as my router was broken. On the 1st of March 2021 when i logged into my rain account, to my surprise i owe R 814.00. I need an explanation to what this amount is for as i have paid for all the month i have used their data for, also their slogan is that "there are no contracts" therefore what am i owing for (again). Can they please give clearity as i am not going to pay this amount.