This was included in our WISC-IV write up.  It doesn't mention "High Superior" so I'm not sure if it is worth anything.  This is the Canadian version so maybe "High Superior" was lost when they translated it - ha ha.  
Very Superior 130 and above  98-99.9th 
Superior      121-129        92-97th 
High Average  111-120        77-91st 
Average        90-110        25-75th 
Low Average    80-89          9-23rd 
Borderline     70-79          2-8th 
Impaired       69 and below   2 and below
This is just a thought, re another possibility of the meaning of "high superior". One of the testers we've seen referred to the official category names, such as "Superior" and then added a "high" or "low" depending on the range within the category. 
It sounds like your communications so far have all been phone calls or in person - I'd suggest writing a brief letter stating specifically what you are requesting, and request that you receive it within 10 business days. If that doesn't produce results, send another written request for a copy of your child's full file - you might have to pay a slight fee for copying it. 
Good luck!
polarbear