Connecting Arduino + GPRS Shield + TFT Shield

I'm working on a school project and trying to connect an Arduino Uno R3 to a GPRS shield which is then connected to a TFT Touch shield.

I've been able to make the touch shield work when connected directly to the arduino but once the GPRS shield is connected it stops working, which makes me think that some of the pins are trying to be used by both? Is there any way to fix this?

GPRS shield being used: SIM808 GPS/GPRS/GSM Arduino Shield

Touch shield being used: Seeedstudio 2.8'' TFT Touch Shield