I might take this to court cause I have no doubt I would win this case. Betting same amount at different accounts is proof of nothing. You would either need to prove that the same IP logged into several accounts or if using a VPN that the same device logged into several accounts with a VPN. To avoid this you would only need to pay 140 euros to me.
Great idea, should only cost you a few thousand excluding flights and accommodation in Ireland (for each court sitting).
It is very strange that there are no other complaints on the whole internet about non-payment from Betballer aside from yours and one other at the exact same time. This book has been around a long time, they have a very good reputation.
Good luck with your case.