Here’s what’s going on.
Your new card is associated with the old card. It’s considered a replacement card when a card is lost, expired etc.
Payment Network Operators (Mastercard, Visa, American Express etc.) have a service that merchants (Google) can subscribe to called Automatic Billing Updater. The merchant had your old card in the updater and when the PNO made a replacement number, the ABU updated the merchant. The Google ad subscription was billed to the new card before you even received yours probably.
The root cause is the old card had its information compromised by scammers and they have used it for various services or products.
The bank will need to ask the PNO to suspend the ABU or mark your account as fraudulent with the PNO. But just issuing new cards will not stop the fraudulent billing.