Can our credit union refuse to release liens unless paying off all 3 loans with the credit union

we have 3 car loans at our local credit union. 2 of those loans are less than $1000 from being paid off but they are saying they refuse to release the titles to those until the 3rd loan is paid off. The third one is a seperate loan and the car still has at minimum 3 years before it will be paid off.