Fidelity is correct in that they can not change the 1099-R because it is not wrong "from their perspective". Fedelity held the money in a ROTH for less than 5 years. How long it was held in a ROTH by the predecessor doesn't matter (to Fedelity). But it does matter to you.
If you will enter the 1099-R exactly as printed it will all work out. After entering it, continue working through the program and pay attention to the small print on each screen as you work it through, so you don't mistakenly answer NO where you should answer YES (or vice-versa). Once the program "knows" this money was in a ROTH for more than 5 years (counting back 1826 days from the date of withdrawal) it's taxability should be "cancelled out" if you've made the correct selections on each screen following the initial 1099-R entry screen.
