The most obvious error would be the Paragraph styles not existing. Since you are opening a txt file it will contain only built-in stylenames and the styles you are trying to apply are not built-in names.
So your macro should either create those styles or import them from a template that does contain them. I've added a line to import the styles from the attached template - this will be Normal.dotm unless you have configure the attached template differently.
You don't need wildcards if the styles are Paragraph styles - the entire paragraph will get the style if you apply it this way.
Code:
Sub TextChanger()
Dim arrFind() As String, i As Long
'Application.ScreenUpdating = False
ActiveDocument.UpdateStyles 'import styles from attached template
arrFind = Split("ALB,TRI,QIU,FSF", ",")
With ActiveDocument.Range.Find
.ClearFormatting
.Replacement.ClearFormatting
.Forward = True
.Format = True
.Wrap = wdFindContinue
.MatchWildcards = False
For i = LBound(arrFind) To UBound(arrFind)
.Text = "@" & arrFind(i)
.Replacement.Style = arrFind(i)
.Execute Replace:=wdReplaceAll
Next i
End With
'Application.ScreenUpdating = True
End Sub