Lenovo — Does not give as promised service

I purchased a lenovo laptop, on 2/09/2022, in 3 months it was defected, the problem is sparking sound coming from my motherboard i raise a complaint on 27 dec, 2022. they causht that sound is coming from the laptop fan. Then the their service representative visits my house with laptop fan then they found out that sound is coming from laptop motherboard. I said then ok replace my motherboad they orderd on 3 jan and then it was arrived on 7 jan and then his service representative visited my house and then sound is not fixed after replacing the new motherboard also, his service tols me that he took the part with him after checking it at their service center. They will contact me (but he not informed), and he is not picking up my phone call also, and then i called at the customer service they said to me that the motherboard they send to me is defected. (lenovo does not check his product wheather it is working or not. i am a student and this will affect my study.) After that yogesh who is my case head he is so irresponsible he can't contacted me. i sended the message through and then he conatced me. after sending lot of message thorugh his colloges he contacted me and he told me that if the machine is not fixed by changing the motherboard then it was a your laptop is faulty he told me that he will now give me final solution. and then what happen lenovo closes my case id which was [protected] (11 jan 2023) and opened a new case id [protected] what was that they also don't know, and then on they close after i talked with him and then suddenly they again open this on 13- jan 2023 and closed my previous id [protected] on 13 jan 2023. and i called for the reason what was the reason was this it was closed by mistaekly as a repuated company is this mistake was acceptable i have to bear all loses i am a student my study is affected by their stupidity. please help me to out of this problem.