Hi JulieS,
This is something that only you can decide. If you like the general “feel” of latex and it’s only a matter of adjusting the firmness of your mattress then exchanging a layer would certainly make sense because the ability to exchange a layer is one of the biggest reasons for choosing a component latex mattress in the first place. Of course if you don’t like the feel of latex compared to other materials or types of mattresses then a return would probably make more sense.
There are also some suggestions in post #2 here that may be helpful if your mattress is too firm but the first suggestion I would make is to give any new mattress 30 days or so whenever possible so that the mattress has a chance to break in and you have the chance to adjust to a new sleeping surface that is different from what your body is used to (see post #3 here as well).
I would also make sure that you have a more detailed conversation on the phone with Dreamfoam so that you can provide them with more detailed information about yourself and your sleeping experience and “symptoms” so you can take advantage of their many years of experience and the guidance they can provide based on working with other customers whose experience and circumstances may be similar to yours.
Phoenix