The function "append" doesn't work apending with lists of lists?

[Kipos]

?- append([[[2, a, 2], [2, 2, 2], [2, 2, 2]], [[2, 2, 2], [2, a, 2], [2, 2, 2]], [[2, 2, 2], [2, 2, 2], [2, a, 2]]] , [[[a, 2, 2], [2, 2, 2], [2, 2, 2]], [[2, 2, 2], [a, 2, 2], [2, 2, 2]], [[2, 2, 2], [2, 2, 2], [a, 2, 2]]] , X).

X = [[[2, a, 2], [2, 2, 2], [2, 2, 2]], [[2, 2, 2], [2, a, 2], [2, 2, 2]], [[2, 2, 2], [2, 2, 2], [2, a, 2]], [[a, 2, 2], [2, 2, 2], [2, 2|...]], [[2, 2, 2], [a, 2|...], [2|...]], [[2, 2|...], [2|...], [...|...]]]

Above i've got the exampe of my problem.When i try to use the "append" function to join two lists of lists, the result it's not quite good!Can anyone help me please?
Thx