I plan to come to Hong Kong this coming September and I will only stay for 1 full day there. It's said that I can travel unlimitedly on MTR by using Tourist Day Pass which costs $55, and it's also said that I CAN'T use this card to travel on MTR Bus. My question is:

1. What buses are categorized into MTR bus? Does it mean tram, double decker, ...?

2. Do I get a refund after I use this card (before I leave Hong KOng)?