DFR0699 - GT911 touch doesn't work on Arduino Mega 2560?

I'm using the provided GDL library and everything, aside from the capacitive touch, works. 

These are my PIN def:

CK → 52

SI → 51

SO → 50

CS → 3

RT → 4

DC → 2

BL → None

CL → 21 (SCL)

DA → 20 (SDA)

IT → 18 (TX1)

I've also tested two other libraries with no success.

I'm using the default examples that come with the GDL library.