a total ******** National Bank

I have been to FNB branches more than 3 times but the issue on my account remains the same , first they have opened a credit card, a cheque account and now they say i owe them since they decided to upgrade my savings account to cheque account, in the branch they would put me through so many calls sending me pillar to post with no solution, all i want is to close the **** bank account yet i am told i need to pay what i owe them, fnb is a bad bad service, i was told my account will be investigated as i have never app**** a credit card nor upgraded to cheque account i am tired of going to the branch with no solution, kindly close this account i want nothing to do with fnb its a *******.