The cable was the correct cable. All OM3 cables are 50/125. It wouldn't be OM3 if it wasn't 50/125. OM3 150 refers to the quality of cable used, which has a limit of 150m. To go further than 150m then you need OM3 300 (which goes 300m). You cannot have an OM3 cable that isn't 50/125. Whether it is OM3 150 quality cable or OM3 300 quality, it's still 50/125. Obviously for a 30m cable, OM3 150 is more than ample.
The only issue we've ever had, is that sometimes you need a crossover connection rather than straight. This is simply done by unplugging one end, taking off the plastic cable joiner, swapping the pair of cables over and putting the joiner back on. If you just do this to one end, then it makes it into a crossover cable.
We have sold hundreds of fibre cables and never ever had a faulty one.
Rik did ask you to return the cable for testing/refund. Unfortunately we can't refund without the cable returned.