Originally, all quality problems were the responsibility of the seller. But your label and packaging are missing. The most important thing is that you have worn it all day.

First of all, don't wear clothes if they have quality problems. But it took you a day to find the quality problem, and the owner probably won't return it to you.

Second, the most important thing is that the tag and packaging are gone.

Also, although some stores are under the banner of returning goods for seven days without reason, those, some of them are just slogans and have not been implemented. Therefore, you'd better look at the "buyers must read" in their store first, and then negotiate with the owner. These treaties are available in every store. Then talk to the host. Just say that you lost the tag and packaging before you found out that the clothes had quality problems. Also, if you wear it, don't wash it. Try to keep the clothes fresh. Negotiate with the shopkeeper and try to exchange the goods. I don't think returning goods is a good idea. I hope you can exchange the goods.