My question relates to legal practice in the state of:Michigan

A circuit court judge ruled in my favor that the penal sum of my performance bond could not be increased for the intention of collecting liquidated damages. I did some researched and it looks like there is an existing "rule" that states the penal sum can increase only in certain circumstances such as change orders. What is the "rule" and if it is a "rule" then why is the defendant appealing the judges decision? plaintiff