Vichy C Vitamin Serum Shows No Results Despite Regular Use

I purchased the Vichy C Vitamin Serum two weeks ago, paying 1610₺, but I am extremely disappointed with the results. When I opened the bottle, there was a loud sound, and the serum had an unusually dark color. Concerned, I contacted the pharmacy where I bought it, but they directed me to customer service. Customer service, in turn, told me to go back to the pharmacy. The pharmacy assured me it was normal, yet even with consistent use, I have seen no benefits.

I strongly suspect the product was oxidized upon purchase. This is unacceptable for such an expensive item. I request that Vichy address this issue and compensate me for the defective product. Please resolve this matter promptly.