Just a thought - Why not do a test to see if the clutch is assembled correctly and will actually bite? The following test should highlight whether it is the clutch pack assembly itself, or the operating mechanism...

Remove the clutch cable completely and the let the release arm go slack (so it isn't doing anything). Stick the bike in first, make sure the back wheel is clear of the ground, start it (you'll obviously have to hold the clutch lever even though there's no cable attached as its in gear), and see if you have drive.

If you do: the clutch pack is assembled correctly and and the problem lies with the release arm/cable/lever adjustment and alignment.

If you don't: The cluch assembly is at fault and will need another look.

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