Coca-Cola Bottles Keep Coming Flat, and My Previous Complaint Was Never Resolved

I have been experiencing a serious and ongoing issue with 1‑liter Coca‑Cola PET bottles that I regularly purchase from Migros Talatpaşa branch in Alsancak, Konak, İzmir. Over the past month, out of the last 32 bottles I bought (always as 4‑pack bundles), 24 of them were almost completely flat and without gas. I currently still have 8 unopened bottles at home and I am worried that I will encounter the same problem with them as well. One of the flat bottles has an expiration date of 08.12.2026 with the production code LV2127, and similar issues have occurred with other bottles from the same period. I have also kept the receipts, and my total spending on these products in this period is approximately ₺1,950. I have been a loyal and regular Coca‑Cola consumer for years, and I experienced the same problem around two years ago, again in October. At that time, I contacted Coca‑Cola customer service and also submitted a complaint via Xolvie regarding flat products. I did not receive any direct response from Coca‑Cola customer service. Through Xolvie I only received a single reply stating, “We will get back to you as soon as possible,” but even though two years have passed, nobody has called me and no solution has been offered. Having to deal with this quality problem for such a long time, combined with the lack of any proper response, has seriously damaged my trust in the brand. I have been financially affected by repeatedly receiving flat products, and I have also been unable to enjoy the product I intended to purchase. I request that the batch and production information of these flat products be examined and that the cause of the issue be investigated, and if necessary that an on‑site inspection be carried out for the unopened products I still have at home. For all defective/flat products, I request either product replacement or a full refund of their cost. In addition, unlike my previous complaint, I expect this matter not to be left unanswered, and I request a clear response with a permanent solution, either in writing or by phone.