I had a leak in my loft and contacted a roofer who came round and quote £1400 to repair the flashing, replace approx 20 broken tiles and repair the broken cement. As the job progressed there were more issues with the roof than anticipated and half the roof has been replaced with new felt and wooden battens. It's a 3 bed terraced house. However there was a misunderstanding between us and I thought the prices he was quoting for each additional job was the new total price and he says it was for each job so the cumulative total is significantly more than I anticipated. The job was initially £1400 and I thought the total came to £7000 whereas he says it is £18000. I could barely afford the £7000, and have already had to borrow for that. I think the £17,000 is ridiculous and would never have agreed to the work if I thought that was the price. £7,000 is my savings for a year and I literally don't have any more. What do I do? Can I refuse to pay more than what I thought it would be? They've basically finished now.