Garnier Color Shampoo Failed to Cover Gray Hair

I purchased Garnier Color Shampoo 4.0 Brown from the Watsons store at Bursa Zafer Plaza about two days ago. My only intention was to cover the gray hair at my roots. I applied the product according to the instructions and carefully followed the recommended waiting time. However, my gray hairs remained exactly the same, with no coverage effect at all.

Even though the box does not clearly provide proper usage instructions, I applied the product following the short-term use approach recommended for this type of product. Despite this, it completely failed to deliver its most basic promise: gray hair coverage. This was extremely disappointing. Not only did I waste my time, but I also realized that the product was completely ineffective.

I am requesting an explanation from Garnier as to why this product failed to cover gray hair, and I also request a refund for the product I purchased. If necessary, I kindly ask that I be contacted through the Watsons Bursa Zafer Plaza store or via my contact information so that my issue can be resolved.