PATHETIC CUSTOMER SERVICE

I bought products that was on special instore and when I got home I realised that they overcharged me and did not give it to me for the discounted price. I emailed them on the 8th April 2024 and they responded 2 days later that they have escalated the issue and will come back to me. I even send them proof of purchase but up until now they did not get back to me. How hard is it to check your specials and come back to the customer?