Just get a refund bud.
I know to some mrk2 golfs are desirable and very thin on the ground now but the big picture is, its failed and fucked, they source a engine from the scrappy, bung it in makes sure it starts and stops and that's it give it back which could just be the start of more shit, head gasket failure looming water and oil leaks bla bla
Money back and fuck it off if it was me.