Is there a way to transfer money from the gift card?
Unfortunately, no.

The Google Play Gift Card TOS (US) includes the following which mentions that once a Gift Card is purchased it can only be spent within the Google Play store and cannot be transferred or refunded:


  2. Limitations. [...] The Gift Card is not redeemable for cash or other cards, is not reloadable or refundable, cannot be combined by you with other non-Google Play balances in your Google Wallet account, and cannot be resold, exchanged or transferred for value, except as required by law. [...]


For reference, Google maintains a list of purchases eligible for Google Play balance per country which includes country-specific TOS documents. It's also worth noting that a balance on a Google Play Gift Card is different than your Google Wallet balance.