Return Request

I ordered XPS 15 9570  and received it on 7th August 2018 and very first day it started freezing so I called their technical support on same day and he told me that motherboard is defective, then he told me that they are going to send me a new laptop in exchange of this, and created an exchange order number. Then I decided not to keep this product and return this laptop, I called their customer service on 13th August and customer service person told me that they first need to cancel the exchange order and then they will send me return label for original order and it will take 24 to 48 hours. Now today 15th August 2018 it already passed 48 hours  and nothing is done. I called their customer service again today but there is no satisfactory answer is given to me. I don't want to pass 30 days on my purchase date and then maybe say that now 30 days passed and you can not return the product. Why a company like dell is doing this. Someone  from senior management team must do something for quality assurance and good customer service. Please someone from the management team if they are reading this forum can look in to this matter ASAP.