Arçelik Dryer Not Drying - 4 Repairs & Still Faulty

After a year of usage, my Arçelik dryer began to malfunction, failing to dry correctly before it had even completed its first year. What once took two hours now takes six. I've lost track of how many times I've contacted for service, and despite having the humidity sensor and card replaced three times in the workshop, the problem persists. Every time they return the apparently repaired machine, it takes 6 hours to dry instead of 2. They take the machine away, claiming it's not usual, but the problem persists. The machine, which is only a year old, has already gone to the workshop three times and had four parts replaced. It is either time for a replacement or for me to begin seeking my rights under consumer protection legislation. We're not making progress with the service, and they persistently refuse to grasp my predicament.