Duplicate tickets

We are going to DL in May with extended family. I already purchased park tickets for my immediate family. However, my mother in law did not know that and bought us tickets as well. Disney will not refund or cancel the tickets. And the tickets can strictly only be used at DL (not transferred to any other park). I get the tickets are non-refundable but come on. Any advice? DL cast member on the phone not helpful.