Amazon Promised Me a Coupon, but I Never Received It

Amazon emailed me with a 40 TL voucher if I agreed to receive electronic communications. I accepted the offer, and on March 19th, I received notification that the voucher had been applied to my account. However, as of today, the 9th day after the voucher was credited, I am unable to use it. I've contacted 4-5 customer service representatives, but the only response I've received is that the issue will be escalated to a higher authority. Why did Amazon waste my time by making the offer in the first place if they weren't going to give me the voucher? They also offered me a voucher for 31.21 TL, which is still pending. Despite the fact that they credited a total of 71.21 TL in vouchers, I was unable to use any of them. The customer service representatives agree with me, but they are unable to assist. Amazon has created an absurd situation. Thank you for the "supposed" voucher; however, I would appreciate it if Amazon could actually follow through on their promise.