I WON'T PAY THIS BILL

I am not happy with the services I received from Rain. I was told my first payment would be on the 1January, to my dismay I am being told I need to pay R323. 47 claiming that I used their 4G services after 6 and I never did. I always arrive at home from work at 17:50 so I have no use of 4G that time as I have 5G. I have never used my 4G router after 6. So I will not pay R323. 47 as my 4G sim it's always inactive after 6.