XPS 13 9370, defective product

Where do I send a complaint letter?

I am having the same problem with my notebook XPS 13 9370 since it arrived to me in February 2019. I feel I can no longer rely on this machine and neither on Dell to fix its functionality from a distance as Dell Support Team has been doing. I need this computer fixed, exchanged, or my money back <A refund is only allowed inside the first 30 days from the Dell invoice date. Dell-Admin> because it has been more than 18 MONTHS of this trouble and I can't take it anymore.

The first Support Request I asked through the chat was on February 26, 2019, I opened another Support Request on September 26, 2019, and the last one was on January 13, 2020. And now the same malfunction is happening again but I'm not able to open a new support request because my warrant is expired.

My complaint isn't about the support received by the technician, your colleague was very attentive and able to solve the malfunction for the moment. My complaint is that the malfunction is recurrent since the first month of use as I explained more than once, and no definitive solution was presented to me until now.

This is a defective product we are talking about and I need a definite solution to this problem.

Kind regards,
Geisa