Flats owners in five run-down tower blocks are facing a bombshell bill of up to £40,000 each towards the “essential” refurbishment of the buildings. The total cost of the work at Margate’s Invicta House and Ramsgate’s Harbour Towers, Kennedy House, Staner Court and Trove Court has doubled to £40 million. Most of the 403 flats are social housing – but 32 are owned outright by leaseholders, who are being asked to stump up huge sums. Thanet District Council (TDC) says each leaseholder will be charged between £25,000 and £40,000 towards its Tower Block Refurbishment and Retrofit Programme. The pro…