Fence stress

The fence is under quite a bit of stress as the neighbour built up the land behind it by maybe a metre or so. The land goes up to the top of the concrete panel and used to be at ground level as we had a fully wooden fence before. It’s a tallish fence for this design. It’s a jointly owned fence and we both paid for it to be installed. Every time it rains it gets worse. We’ve spoken to them about it a while ago but maybe need to do so again as they’ve added more weight including what looks like a water butt which is pressing in the panels. Starting to get a bit worried someone may get injured if it suddenly pops and the land spills out. We live in a rather steep hill area.