I feel your pain, 100%. When we were getting ours done, my partner's brother said he would do it, which we were thrilled at.
In Feb, we ordered the kitchen to be delivered for mid-March, then he told us to get the kitchen completely ripped out and cleared (we had to do that, even though we said we would pay him to do everything, like he would for any other customer).
He said he could start the Monday after it had been delivered (was delivered on a Thursday).
For the first week he was coming and going doing electrics and gas and things like that, which was okay. Bear in mind we had NO means of cooking apart from a microwave, and no sink downstairs.
After that, he disappeared for about a month. We heard nothing more from him (after he ignored texts and calls) for five weeks.
After this, there was a MASSIVE bust up because he finally picked up the phone and my partner had a go at him saying he couldn't just leave us without a kitchen for this long.
He said he was sorry - he'd been busy - but would start coming next week.
Anyway. He started coming, but would come for like 2hrs a day, not starting until mid afternoon despite saying he would be there from 10am each day. Sometimes not turning up at all despite saying he would.
Mid March we ripped out the kitchen. It finally got finished in early August. So that was almost 5 months without having a way to cook proper food. It cost us a fortune in takeaways, meals out, microwave meals. We all put on weight, and now I feel horrible.
It still isn't truly finished. He hasn't finished the plug sockets, and needs to fill the ceiling around the lights. But at least we can use it now.
He had the cheek to text the other day asking why we were getting someone else to do the bathroom instead of using him! Erm, because we want it done before next summer, mainly!