What to say when you've been uninvited from a wedding?

My cousins wedding is quite soon. We have family problems with them anyway, but my grandad forced my aunt to invite us. My other aunt called and said she wanted to speak to my mum privately. It's been confirmed that she's been asked by my aunt to uninvite us from the wedding. We're sure about this, so no point asking us to recheck. What should my mum say?