Been auditing auto repair shop accounts for 4 years and never seen this before. Compared the interval data against the bill and found TOU allocation doesn''t match meter timestamps. The TOU peak window on the bill doesn''t match the current tariff definition.
PSA: Oncor new Rate GV effective next month
Had the exact same problem with PEPCO last year. Took about 18 months to resolve but got full refund.
I disagree with the approach of going straight to the PUC. Try the utility''s escalation process first — it''s faster.