I reserved the shuttle bus last Saturday successfully.
I had the same problem in the first place. I tried several times and finally, just ignor the "0", it works.
i.e. 1666- 81- 3 - 439373211.
The girl can understand simple English and I spoke very limited Japanese. In fact, they just need the date, your name, number of person. That's all.
I've checked with the free shuttle bus schedule. It arrives the farm at 11:30am but back at 4:00pm. Could you tell do we have enough time to join all the animals' activities and shows during these 4.5 hrs (including lunch-time)?