Easy questions really

1) Because they want to/need to make more money to cover the cost of free calls
2) Bad site housekeeping, updating some price mentions and not others
3) They also state in the TOS's that they reserve the right to amend anything at any time without notice

Their common excuse is that the whole service is still in 'beta' but in reality they just dont have enough manpower to keep things correct in all departments.  Work around the disadvantages by using the credit for chargeable calls you would have made anyway (mobiles and chargeable countries) and pack in as many free calls during your 120 days as possible.  You are still going to get good value.

There is absolutely no point in getting upset with these guys, it gets no attention - use the energy constructively !