Box gutter replacement

The joint which sits in the middle they just fitted with no sealant. It rained a few days later, I had water running in my house, I phoned the owner Azeez he came to check it out told me he fixed it.. I had one last check to see what he has done, once again he put flash band on it.. It rained and leaked again.. I am waiting for him to fix it.. I have paid him quite a bit.. Overall he's unorganised, not always there to check if he's guys are working correctly, their workmanship is poor.. I would not recommend this business to anyone. More damage was done than repairs.