Window double glazing?

I have just had a new window fitted, but all of the edges of the beading have little gaps in them, they havent been mitred properly to fit. I called the company back and they came back and just put filler in the gaps. This morning when it was raining the bottom of the inside window pane was wet through, is this condensation. but not only that becuase they were wet through the sealant in the gaps is coming away. should the company put new beading round instead of just filling the gaps, beause obviously if the new window is getting that wet it will keep coming away. Do you think it is reasonable to hold the payment up or knock some money off price until they put new beading up?