Overcharged by Defense, Defense & Associates for service

The situation with Defense, Defense & Associates has gotten worse. Now they're claiming I never purchased the training session, despite me providing the receipt and reference number REF-5AFD3BB6 multiple times.

Dear valued customer, Thank you for bringing this matter to our attention. We at Defense, Defense & Associates take all customer concerns seriously and are committed to ensuring your satisfaction. We have reviewed your complaint regarding our specialty food item and have initiated an internal investigation (Reference: REF-5AFD3BB6). One of our specialists from our Client Satisfaction will be contacting you within the next 12 business days to discuss this matter further and work towards a resolution that addresses your concerns. We appreciate your patience and look forward to resolving this matter to your satisfaction. Sincerely, Robert Smith Customer Experience Specialist Defense, Defense & Associates Customer Relations