Mobile operator

function calculateSumForService(input){
    let contractLength = input.shift();
    let mobilePlan = input.shift();
    let mobileInternetIncluded = input.shift();
    let paidMonths = Number(input.shift());
    let monthlyFee = 0;
    let totalSum = 0;

    if (contractLength === "one") {
        switch (mobilePlan) {
            case "Small": monthlyFee = 9.98; break;
            case "Middle": monthlyFee = 18.99; break;
            case "Large": monthlyFee = 25.98; break;
            case "ExtraLarge": monthlyFee = 35.99;break;
        }
    }
    else {
        switch (mobilePlan) {
            case "Small": monthlyFee = 8.58; break;
            case "Middle": monthlyFee = 17.09; break;
            case "Large": monthlyFee = 23.59; break;
            case "ExtraLarge": monthlyFee = 31.79;break;
        }
    }

    if (mobileInternetIncluded ==="yes"){
        if (monthlyFee <= 10) {
            monthlyFee = (monthlyFee + 5.50) * paidMonths;
            console.log(monthlyFee.toFixed(2) + " lv.");
        }
        else if (monthlyFee <= 30){
            monthlyFee = (monthlyFee + 4.35) * paidMonths;
            console.log(monthlyFee.toFixed(2) + " lv.");
        } else {

            monthlyFee = (monthlyFee + 3.85) * paidMonths;
            console.log(monthlyFee.toFixed(2) + " lv.");
        }
    }

    totalSum = monthlyFee * paidMonths;

   if (contractLength === "two") {
        totalSum = 0.9625 * totalSum;
        console.log(totalSum.toFixed(2) + " lv.");
    }
    }

calculateSumForService(['one','Small','yes',10]);
calculateSumForService(['two','Large','no',10]);