The fittings on my Nissens were fine except that it was missing a support bracket for one of the lines which I had to fabricate (just a metal strap and a bolt). It's been 1.5 years so far and it seems fine. I was leery when I installed it because of the missing support hardware and the light weight (probably half the weight of the OE condenser).
That sucks when the wrong part screws up your install day. I lucked out because I bought my stuff 6 mos. before I installed it and didn't need to return anything. Hopefully, you can return yours.