I've had similar experience over the last few months, it's gets a little disheartening :(
Always seems like it's going well then BAM you don't have xyz experience. Funny that, the CV says so, I said so in interviews 1 and 2 and yet you thought somehow I was going to magically get that experience?
I think it's just basically someone else just has that biiiit more experience or they just didn't like me. Which is fine, I don't want to go big 4 I'd just me moving to the same place with a different name.
My advice is try and get some other experience, get your feedback and then try tackling it from another angle. :)