HP India — My laptop caps lock key is not working after 6 times of service

Hello... I am having HP Pavilion 15 AU 620 TX, i have a issue in my laptop caps lock key. If the press the caps lock key it gets stuck and it cannot be able to turn off again. The led light in the caps lock key is still on. I don't know why this problem is happens... I contacted the hp service center and contact the service head and he arranged the service engineer to visit my place. And he fixes the issue it works well only for 3 months after three months i get the same issue. Already i changed the 6 keyboard layout from hp service center and again i contact to service center for the same issue they didn't respond for my queries. Now my warranty is over. Now i have the same issue. If i called to the service center he asked the money for changing the keyboard layout. And also i applied for the replacement they didn't respond my issue and they didn't reply to my mail. This is the good company we are believe this company
products for good quality and long life Material but here they didn't respond my queries. Now i want the replacement or refund to my product.