Lenovo — Lenovo vibe x in service center twice and lenovo service center is not taking action

Address:

Mumbai City, Maharashtra

I have a lenovo vibex, it is 5 months old. The motherboard had crashed after 3 months o[censored]sage. Lenovo replaced the motherboard. It was ok for a month. Again the motherboard is giving problems and also it crashes anytime. I gave it to the service center. After following up with lenovo care since almost 15 days, they are still ignoring, saying somebody will comeback to us. No one is taking any responsibility or any action to resolve the issue. I need refund from lenovo for cheating me on this and wasting so much time and money.