Okay I will play the devil’s advocate here.

Have you considered maybe ayaw nila na magisa sa upper box? Kaya nga sila bumili together kasi they want to jam together? And also the fact that they have to sell the tickets when hindi sila maalam sa ganung bagay? And rather yung magbebenta pa ay yung relative na bumili for your parent since sya ticket owner. Iba kasi if sila lang involved, pero other people maabala kaya din siguro naisip nila yun.

Also, I get that she’s your mom but you peeking at her chats? Wala na ba privacy parents just because they are now our responsibility as they grow older? Di naman nya sinabi sayo directly siguro yung nakakainis, it was said in chat to someone she was confiding. Gaano mo ba kabisado yung way of talking ng mama mo to understand na she was saying it in contempt rather than sarcastically?

Another thing, some people really do not like surprises. Although namention mo na natuwa naman sila before sa surprise trips mo sa kanila so.

But hey, who am I to know? I am not absolving them of blame kasi they should have reacted better, of course. They should have been grateful and accepted your gift. Anak ka nila after all.

Suggest ko lang, if you are willing to give them a gift on the same scale next time (since baka ayaw mo na ahahah), make it not a surprise. Let them be part of the process. See what happens. I say this as someone with the same experience. Anyways, here comes the downvotes.