Time off for the weekends in spend during business trip

Does anyone have a link to the labour laws (in Chinese or English) that regulate work abroad on national holidays?
My company sent me at the last minute to Europe for a trade show over the 228 4-day weekend earlier this year. After months of trying to claim those two days back as days off (I didn’t ask for the Saturday and Sunday, just Feb 27-28), they finally told me that nope, it wasn’t going to happen. Their shittiness is made worse by the fact that not only did they not tell me this before the trip, they even made me work on the previous Saturday (the “make-up” working day for 227).
I won’t be staying with this company for much longer, so I don’t really care about rubbing them the wrong way. I just want to get my 2 days of paid leave back, and if there is a law that says they’re not allowed to do what they’re doing, I would love share my knowledge of it with HR.

There should be a relevant 函 buried somewhere at laws.mol.gov.tw.

(You can always ask the labor department, and for a more reliable answer you can write to the MOL through the contact form on their website. I’ll let you know if I happen to come across anything.)