Samsung India — samsung galaxy s7/ service center damaged phone screen

I am writing this to due to poor servicing of samsung company.
I had bought samsung galaxy s7 from z square kanpur uttar pradesh 6 months ago.
Around 15 days before, it started giving charging issues. It was not charging properly.
I took it to samsung service center mall road kanpur on 23rd august 2017. There, i have said to take backup of my phone so i switch on my phone and took backup. They checked it properly and assured me of only charging issues. They issued me a receiving on which it is clearly stated that phone has charging problem only. And said to take phone after 3 days. On sunday, i receive a call from there and they said to take mobile phone, it's display is gone it cannot be resolved there. I was shocked to hear because i have handed proper working phone except charging issue.

I gone there and told them about everything to each member. But they said to take my phone back. So i talked to their head, he listened and then the worker agreed to me about phone original issue before submitting there. They agreed that it is their mistake. It is their fault and they were trying to impose on me, this is how you behave with your customer.
They have said that they will give me proper working phone on 5 september. But there is no response. Now i have got frustrated. After buying costly phone i have to go through all this. I am really disappointed with your service.
I will have no choice if you will not give me my phone back with proper condition. They damaged my phone and now they are not giving it back with proper condition.
All this causing me trouble despite there is no falut of me.

Kindly repair it and give it in well functioned condition.

If this is your service facility then no one will bought samsung's phones.
I hope you will understand my problem and try to resolve it quickly. I want my phone back.

Either provide me new phone or repair old one properly with no damage.
I am attaching a copy of receiving which i got at service center, it states that mobile phone had only charging issue.

Regards
Ashish kumar tiwari
[protected]@gmail.com