Guttering

[ste b]

Another question for you peeps,....... someone called about there gutters so i call to have a look,there gutters have been re-placed with plastic about a year ago and have not stopped leaking since,they have been jointed on to cast gutters with silicone thats where its leaking,and i mean a lot of silicone along with what looks like a wide roll of extremely sticky black ****e, what looks like the sort of stuff peeps put along where a roof meets the wall,like lead flashing but different lol.forgot the name lmao, abutment i think,anyway i cleaned it all up like new to save customer some money,got rained off after that......anyway my point is how would you fix to stop it leaking and what would you use......i wanted to rejoin with bracket properly to old cast but i cant find any sort of fixture that will do it,is there one? my other option which would cost the customer was to fcuk next door put a stop end on and put own drain pipe on,but there is no drainage and that mean waste water all in garden,which i can get around but again its at a cost,just incase you wondering about next door,they dont speak to there neighbours lol. not 100% sure if silicone is best answer i know its the cheapest,any ideas ............

anybody here lol............