Homend Alex Laser 1281H Vacuum Cleaner Falling Short

Hello, I purchased the Homend Alex Laser 1281H model product in January, which promised a runtime of 100 minutes but can only operate for 45 minutes. Despite being sent to the service center twice, no solution has been provided, no equivalent product offered, and no part replacements made; only returns are accepted. There's no offered solution, and even with 100% charge, the product can't clean two rooms. Opting for a refund is the easy way out. For this chronically faulty and irreparable product, I demand either compensation for the difference or an exchange for another product promising a 100-minute runtime. I have filed a complaint with the Consumer Arbitration Board. Customer service is unresponsive, and the authorized service reports contain accusatory remarks against me without acknowledging their own mistakes.