i_effective=14% (compounded monthly) ==> i_nominal = 13.17% compounded monthly.

Use Pv=$25000-$2500=$22500, i=13.17%, pmt=$500, Fv=$0 ==> n=62.4 months

Use n=62 months, pmt=$500, Pv=$22500, i=13.17% ==> Fv=$196.99 to be paid 1 month after the last $500 at n=63

Pv=Present value

Fv=Future value