T app - Payment cancelled at Tapp but amount not refunded from last 2 months

I had made a payment of of electricity bill through T App but it has been cancelled and the amount has been debited from from my credit card on **th march **** and from then i had been in follow up with the t app customer care and emailed them the all proof and statement and following up with them daily but my amouby has not been refunded yet till today .below i

Dear user, Sorry! your transaction bearing reference number MGOV***************** was unsuccessful at the bank. If any amount is deducted from your account, it will be refunded to your account.,c