Missing parts

[Keith124]

Hi all I've just purchased a grandland x 2018 plate but having difficulty trying to get some roof bars what will fit it it's a normal roof with no bars on it all I've got is 4 threaded hole underneath the doors .So I've just bought a 2nd hand set of thule square roof bars which where on a grandland x but they won't fit mine the round peg which locates into the hole seems to be short so have I got something missing any advice is much appreciated  thanks