State Bank Of India [SBI] — never respond to mail or call back and when we call its always put on hold

Address:

Raigad, Maharashtra, 410206

I booked my oet examination test date on 16 th December from SBI credit card for which 30561 was deducted. SBI card accidentally deducted the same amount again from my account, that means they deducted twice for one booking. for the same reason, i called sbi customer care, first of all there call never get connected so i put them a mail explaining in detail. SBI refunded extra deducted amount and also they sent mail to examination body to refund my money for which they say they have reversed.
now my current scenario is oet examination body is saying to pay money again and when I ask sbi they say that they have paid them.
now when I want clarification from sbi they are not responding to mail nor calling back, such pathetic credit card service.