I get that you're (!%()*%! but even if you still want to choose to hate them (which I don't recommend, but that's opinion, not fact), do yourself a favor and learn something from this experience. If you want good online shopping with dealers - learn to be a good online shopper. Avoiding them may be one lesson, but there are far more valuable lessons here you shouldn't miss that will help you in the long term.
I've had issues with many of the major online dealers and retailers - would you like me to list them all so you can avoid them? Most people don't do that which disproves the logic "bad experience = avoid forever".
A more appropriate title and lesson might be: "Don't waste your time (or be very careful) ordering large parts from online dealership retailers". None of them will get this right 100% of the time.
In the future, if you order large parts:
1. Look at the 10 biggest online retailers with discounted prices and see if any are close enough to drive too.
2. Ask your local dealer to match the price of the large part.
3. If you're dead set on online order - ask up front about total shipping, return, warranty, costs - if they can't guarantee it, don't buy it. But honestly I would just avoid it, particularly for someone doing small volume like you're doing. There are *many* issues, you only ran into one of them. Sure you might get lucky next time but that's anecdotal.
All of which I've done like 100+ times.
Now - about their mistake.....
I've ordered and shipped car parts for decades....US, Alaska, Australia, New Zealand, Europe, Hawaii, Puerto Rico, South America
I've had issues with multiple online Subaru dealers - but I think mostly just once each, so no patterns or trends, just honest mistakes.
What I can tell you for certain is that you will *never, ever* get walk-in, hands on, expert service like you can from a local professional when dealing online. There's content/digital/ordering/computer side, processing, picking parts, boxing, payment, shipping - there might be 1, 2, 3, 4 people involved at a distance and that leaves room for mistakes. They don't happen often - but statistically it's going to happen. 1% of the time...or whatever it is. I've done enough that I've seen it. The more important question is if one dealer is egregiously mistake ridden more than others - I haven't seen that to be true with the online dealers so I've never posted any of the issues - even some really big one$$$.
Additionally - I would not order large parts from online Subaru retailers. They're not professional shippers and they can do it and reasonably well considering - but it's far from a specialty.
Large parts have a lot of issues - communication, pricing, packing, shipping, damage in transit, trying to claim warranty or insurance on large parts...the normal possible mistakes are amplified and additional mistakes are present when doing large items. It's best avoided particularly for average car owners. I'm generally not in a time fix and understand these things well, I've seen lots of issues, they don't phase me - so it doesn't matter at all to me.
For example - some aftermarket parts companies that sell on ebay - they're selling the same part thousands of times - they're "better" at this and have a more predictable and repeatable service after the sale. Subaru retailers are not there yet, and I doubt they will be any time soon logistically speaking.