My main advice is never say "never".
It was a long time ago and slightly different when I applied to the Navy for a university Bursary as a pilot. I failed pilot but was offered a place at Dartmouth prior to Observer training. By then I had started my degree and decided to see it to the end (grants and no tuition fees then).
I came to my senses and realised that on a grey ship for weeks on end I wouldn't be able to go to the pub and chase women on a regular basis so applied for the RAF. I passed both pilot and nav this time (same tests as FAA but I'd prepared) but I was offered Nav as the scores were better. Politely declined saying I would reapply to be a pilot as long as age was on my side but not shutting the nav door (Remember that they want you to be an officer first and pilot/nav second). Got in as a pilot, convinced I'd be chopped and go Nav but determined to enjoy the flying in the meantime. Imagine my surprise when, despite many hoorendous faux pas, it was other guys getting chopped and I ended up with the best job in the world.
Alot has changed in the world since then but some things remain the same.
1. Perserverance - enough said. All the above was after 2 previous attempts at RAIB so it took me about 5 attempts in the end - but worth it.
2. Check what the rules are and what is expected. Then work to those rules. So be polite in "temporarily" declining other offers to perservere for what you want but remember to stress (whatever you really think) that you want to be an officer in the RAF (or RN) first and foremost but you think you'd best reapply for pilot as you think you can do it. etc etc.
3. Don't be fooled by the "aptitude" title of the tests. You can prepare for them. It's not cheating it's using your brain - the most important tool of an aviator. You've done one set of aptitude tests so you know what to expect. I don't know how they do it now but there was plenty you could do to practice beforehand (for 2nd attempts at least). Also find out when you sit the tests if it still a case of no negative marking. If there still isn't any, with 30 seconds to go on the paper tests, just guess all the remaining answers. It is a case of getting the best score.
4. Don't fall for the "change branches once you're in" line from recruiters. There are a few examples but very few.
It was in the late 70's early 80's I did all of the above. Many things will have changed but I expect the basic principles will still apply. Finally, best of luck. I may not get even one number in the lottery every week, but I will never deny that I was, and still am, a very lucky man to do what I do for a living.
All the best .
Blakey