Please note that the slice card cannot be used for ATM withdrawals or any wallet recharges (Paytm/PhonePe,etc)
Other than this you should be able to use the card for any online or offline transactions. If a specific transaction failed then please share below details to help you better
1) Merchant (where you tried to use card)
2) Transaction Amount
3) Date of transaction
In cases of transaction failure, the amount is debited from your account then it is instantly refunded. In case you have not received the refund then please visit the "I have a refund related issue." section and raise a request with the required details and we will assist you further.