Wow.
I would be crawling up Fidelity's @ss on this one. Of course you can rollover a pension into an IRA. It may have a few names, but lump sum rollover and defined benefit to defined contribution rollover, come to mind, but it sounds like you got hosed by bad advice. I guess I'd need to hear the timing of the transaction, and what the amount of lump sum was to say how bad this is, but off the top of my head:
20% mandatory withholding that you'll have to wait til tax filing to get back
10% Penalty tax (if under 59.5) and
Possibly limiting your contributions to an IRA (if, as poster above stated, you were already making those contributions).
Last question... Presumably Fidelity asked what your income is for the year, but did the extra funds getting paid out push you into the 'non-deductible" IRA category? If so, this will complicate your tax returns in retirement for many years.
Also stated above, you have a very limited amount of time to try to get this rectified. Once you pass 60 days, it is difficult to go back.
Edit to add: If this was done by phone, the call was almost certainly recorded. Someone at Fidelity should be able to listen to the archived call and determine whether you received bad advice or just didn't understand what you were agreeing to.
Ridin' 'cross the desert. . .