Claiming the money back from a travel agent upon cancellation of the trip

Dear sir/madam,

I have booked a tour package to Europe for myself and my family. Two days before, the trip visa of my wife got rejected, because she was switching jobs at that time and her UAE visa was in transition.

So I had to cancel my trip. My travel agent claims that he will not be able to return my tour fees paid to them.

Can I register a legal case against them and claim my money back?