include a cells contents in the next cell if the contents are too long?

Isn't it not simpler to choose Wrap Text in B39.

Otherwise you could merge B39:C39.

But note, I can't believe I'm suggesting merging cells. Most of avoid this functionality like the plague since it just causes too many problems with anything other than simple workbooks, and which can seriously compromise macros.

Thanks,

see this picture just above the cursor the, I want the light blue box to have a white line in it like the navy one has - how would you make it do that?

Also, do you know how i'd make the light blue box [just above cursor] horizontal [at the bottom side] size be the same as the others? You can see it juts out slightly compared to the bottom of the boxes [horizontally] left and right of it

You really need to upload the actual workbook. These things are easier to understand if we can see the request in context.
However almost certainly you are setting the border colours to white, where the cell background colour is other than white.