Annamalai University — money deducted from sbi account but annamalai did not give me any confirmation

I have paid the course fee of amount 3847.20 for p. G. D in retailing via online mode. The requisite amount is deducted from my sbi bank account but the payment receipt is not generated. No confirmation mail is given to me about the payment. I am unable to process further. I want a refund of the amount as payment has failed as notified by annamalai university. Please refund the amount of rupees 3847.20 in my account. The payment was made on 28 july 2018