Leaks on different roofs by a not so good roofer

[Froglet1]

Hi,
I paid for my roofs to be fixed, maybe I should have hired someone different!
I have a tiled wall regular tiles, that meets a pitch roof Redland 49 and there's a large gap where they meet
I don't know what is meant to go in there, it was lead before the tiles were changed,
I asked them to sort but not seen or heard from them for over 4 weeks so it's going to be a DIY job
but I have not dealt with interlocking tiles before any advice would be most welcome

 

[ree]

OP,
This is a confusing double post - why not ask mods to remove it?