I took divorce by mutual consent. Both children's custody was given to me.?

No mention of visitation rights was done at the time of divorce proceedings.Now the their mother has asked for visitation rights under section 12 to 23. The judge has given interim orders that I have to travel 180 km with children to my ex-wife's home town every month on first Saturday. When she has not been given any visitation rights in the original divorce decree under sec 13B how can now another court at her home town order such rights. Children feel very tired after such tiring journey to and fro. Total 9-10 hrs. travel and 5-6 hrs stay makes them ill and skip school next day. If she can come to meet them then its fine , I don't have any problem. Is their any legal remedy to prevent children's hle of travelling