I checked this, cable And the pin are missing. There are only 19 wires.
It's missing the -5V pin/wire and it's not a problem (only needed for VERY old peripherals). NO newer PSU's have one. The problem doesn't lie there, trust me.
Take a look and note the missing pin.
If you tried to file a claim for that, they would just laugh at you. Not saying there may not have been something wrong, but I promise you that the "missing" pin/wire wasn't it.