IT`S A DISH RACK BUT A , B & C DON`T FIT

I bought a double storey dish rack for my son`s kitchen, got it home, opened the box and looked at the 4 easy steps to put it together . 2 part A`s. Now these are to be fitted into part B. The diagram on the directions shows part B on level 2 of part A ....but it doesn`t fit ......it kind of fits on level 1, but it just falls over .... Now part C goes above part B.....again it doesn`t fit ..... It may fit on the lower level but as I was born with only one pair of hands, it keeps falling down. I`m not making any progress and there are cutlery holders to be added to the second storey which also keep falling down. The diagram looks so easy ......rubbish, nothing fits . Now this puzzle comes with a tray , I am left with parts A, B and cutlery holders on the tray with the useless directions! It needs an engineer to construct , welcome home Dale .