State Bank Of India [SBI] — bill still coming after full and final payment

Address:

Mumbai City, Maharashtra, 400095

At least two years back i have done my full and final payment of my sbi credit card the executive called me please makeup full and final payment after that i mail you the full and final settlement letter but after my payment that executive not picking my phone totally discontinue and second month i received the bill from sbi credit card it's almost 500 or 600 rupees so when i have done my full and final payment and my card is blocked my account is cancelled so why sbi send me the bill and in last 2 years sbi sending me a bill regularly every month and without my any expenses the bill amount increases almost 5000 rupees lots of time i called sbi credit card call centre and executive told me this is your balance please pay full and final amount and close your card when my card is already closed how do i close again so please suggest me what can i do