MTS / Sistema Shyam TeleServices [SSTL] — I'm complaining about the irrespective charges

Address:	600056
Website:	Mts postpaid data card

This is Karthiga here
My Mts data card # [protected]
This is inform I have raised lots of complaint against my network issue and I spoke wit lots of agents from Mts
None tried to rectify the issue
Disconnection request was given after clearing my outstanding
A lady from retention called me to convience to use the service
Then I tried to use the service m it was no use and I did wasted hell lots of money paying the bill
There was a unprofessional call from collection agents asking for payment
Few days back I contacted ur agent since I received threatening call from court and Cust care rep told me don't go beyond those calls since that was given from our end by Mts legal adviser
Lastly wen I denied to pay my bill
collection agent convienced me to pay 2100 so that they can refund the device amount which was ₹800
Please assist
This is the such a worst service I have experienced so far
Looking for the speedy response
I did received threatening call from Delhi high court
Finally I did paid 2200 using my credit card which is of no use