State Bank Of India [SBI] — complaint about customer care response to customers

I am not at all happy with the customer care people working in credit card department. They always speak rash with customers which spoils reputation of the bank.
My issue : one of customer care executive called for taking flexi pay. After having long conversation with her, i have converted to my credit card amount if 50000 as flexi pay. But unexpectedly i have got amount and i paid it totally by my next bill cycle, the same already informed to customer care executive before converting into flexi pay. After paying amount i have given call to customer care and asked them to cancel flexi pay process as i paid totally amount. They said if you close now you have to preclosing charges and corresponding taxes, i said it was informed me that if i pay the amount by next bill cycle their would be no charges applicable and i conveyed the same the customer care executive. But he/she is not at all listening toy words and speaking rashly towards me. I don't understand what these people think about customers if this is way it goes bank surely losses it's reputation. The way they speak with customers is not at all correct. Kindly take it as a positive way and correct it.