How long for refund of Hangzhou Transportation Card?

1. I would like to visit West lake by bike but I stay in Hangzhou for 2 days only, so Do I need to buy the Z card? If yes, Can I buy it at Hangzhou Tourist Center is located in Huanglong Sports Centre?
2. Can Z card be used for bus and metro also?
3. Can I return the Z card and receive a refund at any metro station or Passenger Transport Central Station?
4. Can I get a refund immediately? or How long can I get my refund (by cash or credit card?)