Copied parts of my cell phone bill to an Excel file for sorting. When I go
to sort it gives me an error message that merged cells must be identically
sized. Help tells me This error only appears if you attempted to sort a range
of previously merged cells, but not all cells in the sort range were merged
or are not of the same size.

To avoid this behavior, unmerge all the merged cells in the range, or merge
all the cells in the range to be the same as the largest merged cell grouping.

How do I do this?