Hmm I wonder why the gutters overflow. What’s the betting both downspouts are blocked in one of those bends too? Both downspouts happen to be inaccessible safely by ladder. The garage roof is fragile old asbestos that is started to crack so not a great idea to go walking up there even using planks. Downspout on the back is also impossible to get to as the conservatory is in the way. Oh and they also want the whites cleaned after the gutters & downspouts have been checked, cleared and water tested to make sure there are no leaks and works as it should. What do you think...? Apart from do a runner.