yes, that's correct for the pHAT, 0x48 is the address of the ADC chip. The HAT pro version should display the same address as well as 0x28 for the Cap Touch.
Since you've got LED lighting up it seems you've got power to the board. You could check the header joints for any problems, such as pins hanging up in the air but it's not always easy to tell with SMT headers.
If you can't see anything unusual, then I'm afraid you likely will have to contact support@pimoroni.com and get it swapped :(
