Unbelievably bad skylight contractor

Called them to do a small skylight in my loft. Paid deposit and they arrived a couple of days later. That’s when the nightmare started. Manager had no clue how to install the flashings. The install cut everything. Was supposed to be installed without cutting any flashings. Damaged surrounding timber and messed Waterproofing on solid wood floors. When they left my house I could see the sky through gaps in the flashings so I did a water test. The skylight leaked terribly. Called back and they watched an online video on how to install skylights. These guys where total inexperienced and 3 weeks later still haven’t come to sort out the problem. Stay away from them.