Hi there,
So yea, it is a Feature not a bug, also known as I2C in this case
- Simplified Interface: The display adopts a serial SPI interface and only requires the SCK and SDA connections to the main controller. This greatly simplifies user operation and saves time on wiring.
There is plenty of example code here for this exact unit. use the search and you will find it I have one on here with the similar display, connected to the Expansion board.
No, use the Wire lib and the I2c pins.
All pins are available on expansion board BTW.
Is it this one?
HTH
GL 
PJ 