Worldline Sold Me a Faulty Battery for Ingenico POS Device

Due to a malfunction with the Ingenico fiscal POS device, I contacted the Worldline support center and filed a complaint. When the technician arrived to inspect the device, they informed me that the battery was faulty and needed to be replaced. I paid approximately ₺1600 for a new battery, but it failed to power on the device. I called the service again and explained the situation; they confirmed the battery was defective and advised me to report the issue to Worldline. Despite a week having passed since then, no one has contacted me. I call every day, and they keep saying, "Your request is active," but no one is resolving the problem.