Been there.
I used a nice honest guy to do my patio but tbf he was a general builder so like you, within years the flags were rocking etc.
Last year I paid a specialist to redo it. Twice the price but the difference is amazing
The previous guy claimed to be a specialist
I used him because he was a parent at the school where I was a teacher and all the people I knew at the school said he was good
and I knew his kids were some of the good kids at the school
At the time I believed he had taken on a large contract with Warrington Counsel and bittne outt too much
and so left a cuple of works to do the job here and not had time to supervise it properly
but he has taken every shortcut available and cocked up a lot of stuff - that the current bloke is quit e happy to point out
but on the other hand - if they were not there to point out then he wouldn;t be able to
so overall I have been convinced that any lingering thoughts that he was just a victim of his own ambition and did try to do it right - have been killed off
if not then he would have noticed and fixed things when they were doing it - because he did come round most evening to see how things were going