Mobile Charging Socket

I bought Nokia Lumia 610 15 months ago till bow it was in very well condition , since 2 days there was problem with its lock key I went to Nokia Care at Lower Parel near Deepak cinema they told me there is problem with its lock key only and changed it
After reaching home I found mobile is not getting charged at all I again went to same service centre on the same day they kept mobile for 3 to 4 days saying that there is problem in Socket come on Monday it will be handed over to you .
On Monday enquiry they told me problem is there on the mother board will take 2 days more after two days enquiry they told phone may be dead also next day on 9th July ,when again I went on Nokia care they told Phone cannot be repaired we need to send it at Factory and will take 15 days and will charge Rs7800.
I stricktly denied to send there because cost was too high. When I call by this mobile my mother I found she was not able to able to listen me I.e. its Myke also got damaged because of Nokia care , its speaker also not remained so good My fully phone got defected neither m able to charge it ,
Please listen to my complaint Nokia care is fooling me again and again , my cell not remained like before its as good as loosing the phone , Its all Nokia care fault.
I want my phone in the same condition as was before giving to service center