Appointment scheduling issues with Family Practice Foundation

The situation with Family Practice Foundation has gotten worse. Now they're claiming I never purchased the customer support plan, despite me providing the receipt and reference number REF-FB5AC34D multiple times.

Dear valued customer, Thank you for bringing this matter to our attention. We at Family Practice Foundation take all customer concerns seriously and are committed to ensuring your satisfaction. We have reviewed your complaint regarding our headphones and have initiated an internal investigation (Reference: REF-FB5AC34D). One of our specialists from our Customer Advocacy will be contacting you within the next 9 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, Patricia Harris Director of Customer Success Family Practice Foundation Customer Relations