Luckily, it is not all risk on me personally, as I registered an Austrian Limited 2 years ago. Nevertheless, now it is time to sort things out with clients. I hope most of them are as cool as the biggest one. Just got of the phone with him - and he just said, okay, let's shift the budgets, no problem.
@kaiser some advertising budgets got out of hand, and a simple miscommunication between two servers created the problem - the receiving server allowed setting budgets to zero. but interpreted it as no input (false).