If I have proof of purchase from the pawnshop I bought it from. How can I get the iCloud activation unlocked.

Apple already contacted her about removing her iCloud. She gave Apple permission to remove it because she is took far outside of Dallas area. And I went to Apple and they said that they can’t remove her iCloud from the phone after they said they can and after the owner of the iPhone said it’s okay to remove her iCloud from the phone.