A former Goldman Sachs banker is facing a £200,000 court bill after being sued by millionaire neighbours who claimed a refurb of her Knightsbridge flat left their home plagued by "extraordinary" levels of dust, preventing them hanging their laundry indoors. Leda Sara, a former banker turned interior designer and estate agent for the mega-rich, was sued by Samuel Wagner and his wife Jennifer over a mammoth five-year stop-start refurb of her £1.6m apartment in exclusive Lennox Gardens. Swedish property firm boss Mr Wagner and his wife complained of ceilings cracking due to incessant banging in the flat above and "extraordinary" amounts of dust generated as Ms Sara's home was stripped back to a "shell." Leaks from a sprinkler and a defective shower tray after the building work was eventually completed also led to significant damage, with one of the ceilings in their £1.4m flat collapsing, they claimed.…