Lenovo — Terrible purchase

My purchase with Lenovo has been the most terrible experience I have ever had in my life. I bought Yoga C940 Intel (14") - Mica from the Lenovo website and once I received the device one of the buttons was loose!. After one month of frustrating follow-up with the customer service! they send me a replacement. My experience with this one was more terrible and after 40 days it is not powering up!. I have been requesting a refund for the defective product they are selling and have called them at least 20 times, and have sent a hundred emails without getting my money back. They just tell me that the 30-day replacement period is finished. They do not accept the fact when they sell a defective product, the customer has the right to get a refund. It is like I have put my money in the trash. Avoid buying from Lenovo. Customer service is just wasting your time and you will eventually reach the position of losing your patience. Honestly telling, I was robbed by Lenovo! I have paid them money and they have sent me a defective product twice!