Activation Lock

Hi guys. Please help me with my device because it is Activation Locked. In that state I can't Use it. It is an Iphone 8. I bought it, and the previous owner can't remember the account and password she used in setting up the phone. We also tried Reseting the icloud but the previous owner can't remember the password and the number associated with the account. I contacted apple about that and they said they could unlock the device but with the proof of purchase. Since the phone is purchased cash, and bought last year, the receipt is not around anymore. So, my question is, what if I show apple that the owner passes the ownership to me? would they allow my device to be unlocked? I really need to help guys since this is the only device i can use in my school. Thank you