Decathlon Stainless Steel Thermos Leaks

I purchased a Decathlon stainless steel thermos, and to my dismay, the plastic inside the cap has inexplicably detached. This has caused water to leak while drinking, creating a bothersome situation as the accumulated water tends to drip onto my nose. Additionally, the collected water in that area is quite unpleasant.

Seeking a solution, I discovered that Decathlon only sells the entire cap for a whopping ₺125, while the thermos itself costs ₺460. It makes no sense to replace the entire cap with a single plastic part. If the issue lies with the plastic in that area, purchasing multiple caps seems impractical for such a flimsy material.

I am interested in acquiring a spare cap, but the current pricing strategy leaves much to be desired. A call for reconsideration and a more cost-effective solution is essential.