美国采购需求：背包、腰包、袜子、运动服饰、登山杖、运动器材

We recently received the trekking poles we ordered, but they're not functioning as expected. When we attempt to unfold and secure them, the top section won't lock in place. As a result, any weight applied causes the poles to collapse, leading to significant safety concerns and making them unusable for hiking. Could you please provide instructions on how to return the poles? We'd like to process a credit for the amount of $47.31. Your prompt assistance with this matter would be greatly appreciated. Thank you!