My code is producing two answers, but it is only supposed to print one.

my code is producing:

payment = fare(1.45,17)

pay2 =

   11.2500

payment =

    1.6900

The code itself is:

function payment = fare(miles,age)
    pay1 =0;
    pay2=0;
    pay3=0;
    if miles <= 1
        pay1 = 200;
        payment = pay1;
    elseif miles <=10
        pay1= 200;
        pay2 = (miles-1)*0.25*100
        payment = pay1+pay2;
    elseif miles>10
        pay1 = 200
        pay2 = (10-1)*0.25*100
        pay3 = (miles-10)*0.10*100
        payment = pay1+pay2+pay3;
    end
    payment = (pay1+pay2+pay3)/100;
    if age <=18 || age>=65
        payment = (pay1+pay2+pay3)*0.8/100;
    else
        payment=(pay1+pay2+pay3)/100;
    end

end

Why is this spitting out two answers when I only want it to return "payment"?