Southern Water failed to fix leak that made basement damp

Tens of thousands of litres of water are escaping in a water-stressed area For the last two weeks the manhole outside our neighbour's property has been leaking in a steady flow. We are now getting damp coming through our basement walls. Southern Water sent someone to investigate but it was impeded by my neighbour's scaffolding. He immediately took it down, but Southern has not reappeared, despite numerous calls from us. Customer service is like pushing jelly uphill and tens of thousands of litre...