I just bought an engl invader II 100 watt amp head and I already had in my possession a sound wizard module.meant to go in place of the existing backplate. I have been very frustrated with the amount of effort I have had to put into finding this cable connector that is supposed to be inside the amplifier. The inside of the amplifier is clean. My simple question is where is the cable connector? I am not paying a 50 dollar restocking fee.