No as per google you can’t do so but with the help of exchange rewards now it Is possible to get 60% of your total google play balance in your bank account or your desired platform by investing your money in Exchange Rewards for more details click here
Yes you can convert the google opinion balance into real cash by just simple steps click here
As once recharge code is purchased it can not be refunded but if you download exchange rewards then you can get 60% of your total value of redeem code for more click here
As there is no official way to get back money from google play balance because as it is a non-refundable balance but if you Download exchange rewards then you can get 60% of your total amount in googlepay/PhonePe/Patym/bank account/UPI address