We paid £4500 upfront for 1st instalment of shed&garage conversion.The standard of the shed is terrible, unsafe &it needs to be removed. We asked the builder to stop work after seeing the shed. We tried to be fair by agreeing £1650 for the shed and what he paid out for the Bifold doors. We required receipts and a refund of the difference. This man supplied a receipt that he’d created himself purporting to be from the supplier,inflated by £800!Now refuses to refund of the difference