I booked a oneworld RTW ticket during the 10% discount period which ended at the beginning of November.

My trip starts out by the following:

YYZ (Toronto) -> MIA -> GUA -> DFW -> TYO.....

Both MIA and DFW are layovers.

I want to change the Guatemala stop to Costa Rica, therefore it will be:

YYZ (Toronto) -> MIA -> SJO -> DFW -> TYO.....

I talked to two agents at the AA RTW desk, each told me the something very different.

Agent 1) Since I am not changing the first international coupon (The Toronto to Miami leg), I need to pay $125 fee to change from GUA to SJO

Tonight, I talked to Agent 2

Agent 2) Any change in North and Central America will trigger a "rebooking". This includes any change up till Tokyo. Therefore, I will be penalized 10% to rebook and I also will have to pay 10% extra for the non-sale price. Resulting in a 20% charge + $125.

I am going to talk to manager tomorrow, but I want to get feedback on what people think before I talked to them.

Also, they changed the date of one of my flights that is towards the end of the RTW. Does that give me any ammunition to fight for a no-fee change near the beginning of the trip? I doubt it but I was wondering.