Overcharged

Good day

i app**** for rain which they have deliver their sim card and yes i use it, but my problem is i app**** for the off peak of 250 but the statement came back and said i'm owing 459 which is not our agreement at all, the off was i used the data from 11 pm to 6 pm and by that time they would switch it off pm the dot. so my question is why they overcharged me to contact them is a mission they would tell to contact support on the dashboard which i did but was not able to submit my query the system will pop out.