Karcher K4 Pressure Washer Warranty Complaint

I purchased a Karcher K4 pressure washer. Shortly after buying it, the unit malfunctioned—it simply wouldn't work. I sent it for warranty service in February, where they claimed to have replaced the pump after a delayed repair. In April, eager to use the product again, I plugged it in, only to find it still non-functional. Frustrated, I sent it for warranty service again on May 4th. Despite opening 7-8 service tickets over 50 days, no one has called me back as promised. They even gave me a technician's mobile number, but B****, the person in question, didn't answer. I reached out via WhatsApp multiple times but received no response. My trust in your brand is shattered, and I urgently demand a replacement with a new or upgraded model. I have also escalated my concerns to Karcher Germany. If this isn't resolved promptly, I will take this matter to the Consumer Arbitration Board for exceeding the 20-day repair period without informing the customer. I now realize that even Chinese brands provide better service than yours, despite purchasing multiple steam cleaners, car wash machines, window vacuums, and hoses from you. I will share my experience of being mistreated as a customer with everyone around me and discourage them from shopping with you.