Unresolved Return Issue with Trendyol Seller

I never received the return invoice, which has made it impossible for me to return the product I bought. I purchased two 50L pedal bins, and although the lid opens smoothly when the pedal is pressed, it unfortunately does not close properly when you release your foot. The seller from Trendyol assured me that I would receive the invoice within 3 business days, but unfortunately, it never arrived. I reached out to customer service and B*** Ha*** assured me that I would receive a response within 3 business days. However, I've been patiently waiting for the invoice from the seller for the past 4 days, but I have yet to receive anything. Whenever I propose reaching out to the seller directly to speed things up, they always refuse to provide any further assistance. If you're unable to assist with this matter, I'm curious about your ability to provide assistance in any other area. I am extremely dissatisfied with the system's design, which only serves to inconvenience and frustrate customers. This complaint is necessary because of the significant amount of time wasted on their inefficient process.