Flying from Greenville, SC to Orlando. Boarding attendent announces "now boarding rows 1 thru 5". I have assigned seat 1A and march right up. She looks at my preprinted boarding pass, checks her computer and then prints out another boarding pass for me. I march down the walk way to the plane and was met by the pilot who tells me I can't get on the plane yet. We chat for a while and then the Boarding Agent comes to retrieve me telling me she let me on the plane to early. Ok Fine no big deal.

10 minutes later, another call to board. I march down the walk way, say hello to the attendent, put my small bag in the rack above me and settle into my seat - 1A.
2 minutes later I'm asked by the flight attendent to show him my boarding pass. Without looking at it, I give him the pass that was just printed by the boarding attendent. He says "sir, you are in the wrong seat, your seat is 25F". Apparently someone else has been given the seat 1A, which I purchased thru the Bundle program,

I showed him my pre-printed boarding pass which did show I purchased seat 1A. I was allowed to remain in the seat I purchased and the other fellow was placed in the aisle seat of row 1.

There were only about 30 people on this flight (8:00 PM on Tuesday 1/14/2010. Non Stop to Orlando)

Now my big concern is - why did the boarding agent move me from 1A to 25F????? She did this without my permission or knowledge.

Very strange thigs going on at Frontier.

IF they print you a boarding pass, pay attention to it before getting on the plane.

I'd straight file a DOT complaint.

I'd like to complain to someone about this. The flight attendent even stated I will see some activity on my credit card.

Tried a customer service number for complaints, but I don't think the guy, probably from India or Manilla, quite understood my issue

How do I go about complaining to the DOT?

https://www.transportation.gov/airco...umer-complaint

Did your "new" boarding pass show 1A or 25F?
I'd check your credit card account to be sure you have a record of your original purchase and to see if you get charged for an upgrade.
If you get charged for an upgrade another pasth is a dispute with the Credit Card company.
I've also found you get a better response to such issues on twitter than over the phone.
BTW I think the call center is in the Philippines.

the new boarding pass showed 25F - which I didn't notice untill the attendent read it. My original boarding pass, which I printed out 24 hours before departure time clearly showed seat 1A.....for which I paid the upgrade fee. I will watch for activity on my credit card.

If I was a "bad guy", I could have taken out the pilot since he and I were face to face with no one else around. Poor security if you ask me.

I think Frontiers gate attendants at Greenville need some additional training

At a lot of stations Frontier land side employees are contractors.

Lots of things I've never experienced before here.

First, Frontier usually starts with Zone 1. Rarely, they will board 1-3 rows. Not 1-5. They do this because the carry on compartments above row 1 are taken up with flight crew luggage. They make row 1 put them above row 3. So if you put row 1 luggage above you, as you claim, you wouldn't be able to do so because they'd point you to the next compartment (above row 2-3).

"She did this without my permission or knowledge"

So you didn't know you were moving to 25F? Did you sit down at any point?

If there were 30 people and you had 1A as you claim, they would have moved you to another Stretch seat. Not to 25F.

Either you had 25F and didn't know how to read the ticket (seen those issues on every third flight during boarding), or you're fudging something.

Complain about what? There was an obvious error which was taken care of on the spot as OP expressly states: "I was allowed to remain in the seat I had purchased."

I would send off a note to F9 commending the FA for sorting out such a simple IT issue in a sensible and fair way.

As an aside, DOT would only become involved if OP were moved to a "lesser" seat and F9 then refused to refund any seat charge, a very unlikely occurrence.

Granted my experience with F9 is limited to one flight but yup, on my flight I purchased stretch seating and didn't have a carry-on and was in Zone 2. Zone 1 was only for those who purchased a carry-on and the GA was enforcing. This was in DEN though with actual F9 employees and we all know contract employees can be wild cards so who knows.