Unable to withdraw funds

I've been playing Lotto using their online platform for a while now and over time have made winnings.each time I play I add to my wallet to ensure my winnings accumulated. I tried withdrawing R1500 and got the notification it was successful.after 3 days the funds returned to my online wallet without any detail on why it did not withdraw to my account, I tried a further 2 times with the same result.i have provided all fica documents and all have been verified over a year ago. When queried with the customer support I was told that the I was trying to withdraw a deposit and needed a proof of deposit which makes no sense to me.sure the value coming into my wallet is proof of my deposit.each time I play I deposit the value of whatever is in my cart so whatever I win should be accumulating independently of my deposits so I don't understand how that makes sense that I'm withdrawing a deposit.also how am I supposed to provide a proof of deposit if I'm not asking, no notification ,no email nothing.surely an online wallet should function simpler than this.now I'm not getting anymore response so I'm just stuck with funds in a wallet I can't withdraw