First thing you need to find out is if it is 3.3v or 5v as the latter makes it worse as you need to buffer the connection first.
SCL and SDA are pins used in I2C but I do not see how RES...BLK fit into that cabling standard
So are there any jumpers / solder pads etc on the back? My guess is that it is switchable from I2C to SPI by either cutting a trace or soldering across a gap.
If it can be switched the RES should be reset, DC data or command, CS for chip select (may need hard wiring) and BLK may be back light.
Did the supplier say it was Pi compatible or give you any clue? They are the obvious choice for support
Do you have a link to the site you purchased it from?
Can you tell the control chip? It may be something like 1306 / 7735 or a totally unrelated number.
Need Pi spray - these things are breeding in my house...