Apple IPAD Activation Lock

Good Day

My mom bought an IPAD about 6 years ago and set it up.

Years passed and now It showing an Activation Lock and she can't remember the Apple ID and Password.

so I tried to get the Apple ID but with no success so then I phoned apple for support but also with little success because we could not find the email connected to the apple ID only an Icloud. So then the lady said I must get the proof of payment now that was a very log time ago and if I don't I will never be able to use it again.

Sorry but I will not accept this, There must be a other way they can help me.