If the surety on a bond fails to pay his obligation and it becomes necessary for the creditor to sue thereon, the latter shall be entitled to ten per cent attorney's fees on the amount recovered, provided he has employed an attorney for the purpose, has made written amicable demand on the principal and surety and thirty days have elapsed from their receipt thereof without payment being made, and the full amount claimed in the demand is recovered.
This Section shall not affect the right to recover interest and costs as otherwise provided by law.