Icloud account blocked out, how to remove
Please help me with my Ipad pro 10.5'' Model A1709. The ipad originally was purchased by my Mother in Laws work who bought it in 2017 but did not use it much. Fast forward to 2020 the ipad became redundant for the company and it was sold off to my mother in law as redundant goods. She then gave us the ipad for our kids to play on. We created an icloud account and logged in and all was fine for a couple of months until our youngest daughter put the password in, incorrectly one too many times and now when we try and log into the ipad the account shows that the account is locked. It is impossible to reset the password. We have called apple and they will not assist with this unless I can produce the original proof of purchase from the store that it was purchased from. The company cannot provide these details due to how long ago the purchase took place. Please can you advise how I can at least remove the icloud account so that I can load another account to be able to download and update the software on the ipad.
iPad Pro, iPadOS 17