I'd don my brightest shiniest Marigolds, pick it up and make sure they see you (better still the parents see you) when you throw it back, then ask them very politely (very very obviously politely) to try very very HARD not to kick the ball into your garden because that is how infection spreads infection spreads.
As a matter if interest - do the neighbours on their other side have the same problem?
The media are already after Andy!
Soops kitchen, a place of reflection, refuge and at times revelry.
I just want to praise you for being so lovely and tolerant. Regarding the ball over the fence, what I would do world be to get my marigolds on, and Chuck it back over the fence.
. At one point we had 5 or 6 balls in our garage, DGS never needed a new football