How to clearcontents of a merged cells

You need Cells not Range:

ws.Cells(j, l).ClearContents

Oops - forgot about the merged bit:

        If Cells(j, l).MergeCells Then
            Cells(j, l).MergeArea.ClearContents
        Else
            Cells(j, l).ClearContents
        End If

Try

Range("A1:A20").Value = ""

No matter cells are merged or not this will work everytime.