Carpet fitting - is this correct?

[2018name]

We have just had carpet fitted - paid more for top quality underlay. Carpet looks great apart from some lines in it were it looks a bit like it has been creased in a couple of places. One of the fitters said this is where the carpet roll (which is rubber backed) was bent to get it up the stairs (??) and they will drop out during the next week. Also we now seem to hae one squeak on a floor board (centre of room not on an edge where grippers were put down) that was not there before - our builder made sure floor was totally squeak free before carpet was fitted.

Does anyone know:

1. If the creases will come out? and
2. How we may now have got a squeak?

Thanks vey much.

What type of floor is under the carpet - floorboards, ply, chipboard? Is it a new room with a new floor?

it is wooden floorboards - a couple were replaced within the last fortnight - the reat have been there for years. Nothing was squeaking before the carpet fitting.