Xiaomi India — problem not solved

Address:

Dakshina Kannada, Karnataka

I am using redmi note 4 that i bought in february 2018. I am facing issues since april, the apps stop working and the message comes that a particular app stopped working and so on. The latest update of mi is not installing on my phone. I have mailed you regarding the same issue before too.
I have been submitting my phone redmi note 4 to mi service center in mangalore, mi mobile field, kankanady bypass road.
It's been one month now and i am repeatedly facing the same issue. They are not solving the problem saying that they are not getting it so it is fine. I have a video of the issues i am having in my phone instead of which they are refusing to accept it.
They told me they sent it to bangalore but not ready to show me the receipt that they actually sent it to bangalore. I have the right to know and it is their duty to show me but still they are not.
They don't have any manners how to talk to a customer. More than 10 times i have visited the store in 1 month. They are being rude and talking so arrogantly.
Today they said to show them the problem with their sim in my phone and again apps stopped working. I showed them instantly. They said they will talk to ho again.
I trust mi so i bought this phone. I am so disappointed with the service. This is the worst experience someone could ever have.
If my problem is not resolved, i would directly go to consumer court this time. I have given these service center people so much of time still they haven't resolved the issue and moreover they are being rude to me now.
I am really disappointed in the service.