A plan is refunded in full on request as long as the eSIM has not been installed. A plan that was never installed is refunded with no questions asked.
Once the eSIM is installed, or once any data has been used, the plan is not refundable. The allowance has been issued to your phone by then and cannot be taken back.
There is one exception, and it is the important one: if the eSIM cannot connect to any of the plan's networks anywhere in its coverage area because of a fault in the eSIM itself or with the network operator, we refund in full even though it was installed. Weak or no signal in one building or area, a locked or incompatible phone, or a setting on the phone is not a fault of the eSIM.