美国采购需求：三头肌绳、阻力带手柄、人体工学哑铃、地雷架、附件配件、杠铃地雷球

I recently purchased a stair stepper from Amazon on March 30, 2026, and I'm having some issues. Unfortunately, the foot pedals keep falling off during use, which is making it quite unsafe for me. I'm really concerned about my safety while using this product and would like to address the situation promptly. Can you assist me with the return process for this item? I'd also appreciate guidance on how to secure a full refund. I hope we can resolve this quickly, as I really want to ensure I have a reliable and safe product for my workouts. Thank you for your help!