Creality CR-10 SE Nozzle Clogs Twice in One Week

I purchased a used Creality CR-10 SE 3D printer, and the machine had only been used for approximately 20 hours in total. After I started using the printer, I experienced a nozzle clog for the second time within just one week. Filament begins to bulge and accumulate at the tip of the nozzle and pushes inward, causing the print to fail partway through. As a result, I am unable to get consistently successful prints.

Because this issue completely prevents printing, I cannot use the printer for its intended purpose.

I have not yet had the opportunity to contact technical support or customer service. I am experiencing significant inconvenience because the printer has developed a recurring problem within such a short period of time despite having been used for only a very limited number of hours. I request that the printer be thoroughly inspected and that the malfunction be permanently resolved. If this is not possible, I request that the device be replaced with a defect-free unit.