Minor, but I'm in the interesting position of having switched employers in the last two months of the year. My new employer gives me 60 days to switch around my new-hire benefits elections. I initially elected $300 in the FSA, but once I saw the bill for my wife's glasses, I increased that to $700 and the increased election took effect a week or so later. As we're continuing to incur medical expenses, I've increased it again to $850.
I asked the FSA provider's customer service whether, if I submit a large expense now, I would be reimbursed the remainder when the increased election took effect. They said that elections can't be changed without a new qualifying event, even if it's within the right time frame from when I was hired.
That's clearly either incorrect or they shouldn't have accepted my first increase.

Does anyone know the actual answer which, and whether I should be expecting the second increase to actually take place?