Cordelia cruisesWaterways leisure tourism - Cordeila cancels cruise at last minute

We booked Cordelia cruise to Srilanka for * families in January. First, the date was changed from *rd July to **th July and we replanned and accepted their proposal. Now Cordiela has informed us at the last minute that they are cancelling our booking since they have a chartered booking for those dates. While they say they as a gesture will give us refund we would like to sue them for compensation of our international travel, mental harassment and mischievous business conduct. When we requested them to resolve the situation amicably they said they are don't care and are ok for us to pursue legal action against the company. All documents can be provided as proofs