Bava Metzia 62 - Interest is Collectable in Court

Why is the Exodus from Egypt mentioned in conjunction with the prohibition of taking interest ? It is as if God said, "I knew who was first-born in Egypt, and I will know those who falsely attribute their money to a non-Jew, and then lend it on interest."

Neshech , or fixed interested prearranged at the time of the agreement, is prohibited by the Torah and can be collected in court. But Rabbi Yochanan says that " You shall not take from him (your impoverished brother) interest or increase; but fear your God ," implies that he who takes interest is obligated to refund the interest out fear of God, but he is not subject to refund it by a court order.