cell.data <- cell.data%>%mutate(Overage.factor=ifelse(cell.data$OverageFee==0|cell.data$OverageFee<=5.0,"Overage<5", ifelse(cell.data$OverageFee>5.0|cell.data$OverageFee<=10.0,"ovearge<10", ifelse(cell.data$OverageFee>10.0|cell.data$OverageFee<=15.0,"overage>10","overage>15"))))
Getting output only for levels like Overage<5 & ovearge<10.