Incorrect pricing

Error in terms of pricing on HTH over black friday. I sent an enquiry on the day of the incident (28 Nov 2021) via Facebook inbox to allow PNP an opportunity to sort out the issue yet more than 2 weeks later I still have NO assistance. I provided the till slip and a picture of the adverti*****t in store - which CLEARLY shows I was NOT charged correctly, yet PNP is dragging their feet in sorting this out. I require a reference number to go to the Ombudsman since PNP is not interested in rectifying this issue.