:Stacking Data

See linked-to Excel workbook below.

My query is probably a bit amateurish but seems to work.

I changed the column headers of your source data at row 2 since they didn't seem to go in sequence.

Result query at cell A31.

Version including source data here for pasting in Power Query Advanced Editor:

let
Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("hZGxDsIwDET/JTNSYjtJk5mdjanqUKkVTIgBid/HvoTCUMFQK2edX5zrODpO7uCIfUieA0SIXrWKqOK0PrUOrEVk0FphtxNnc4t+JQStyWRy02F0ZC6uXlF70PN9mR/rgklDFIMACRCF1HVsy1ktANcIlw+yCz5e59sFYAJJsi2eGENkbcH+dh+RNQS+2uDS4fwjij6WgedtZ26r4g62dmxPIZCHbLD0BdsjtzlCEMXwQBZzoEkSt7CJP0H/+3ttThjPwzEDidnyvq1nr1FMLw==", BinaryEncoding.Base64), Compression.Deflate)),{"Closing Store #", "Final Store Closure Date", "Reporting Week" , "Change in Status" , "Receiving Store #1" , "Receiving Store #1 BASE Volume", "Receiving Store #1 Added Volume", "Receiving Store #2", "Receiving Store #2 BASE Volume" , "Receiving Store #2 Added Volume", "Receiving Store #3" , "Receiving Store #3 BASE Volume", "Receiving Store #3 Added Volume"}),

ChangedType = Table.TransformColumnTypes(Source,{{"Final Store Closure Date", type date}, {"Reporting Week", type date}},"en-GB"),
UnpivotedColumns = Table.UnpivotOtherColumns(ChangedType, {"Closing Store #", "Final Store Closure Date", "Reporting Week", "Change in Status"}, "Attribute", "Value"),
SplitColumn = Table.SplitColumn(UnpivotedColumns, "Attribute", Splitter.SplitTextByCharacterTransition({"0".."9"}, (c) => not List.Contains({"0".."9"}, c)), {"Attribute.1", "Attribute.2"}),
Trimmed = Table.TransformColumns(SplitColumn,{{"Attribute.2", Text.Trim, type text}}),
ReplaceValue = Table.ReplaceValue(Trimmed,null,"Recieving store#",Replacer.ReplaceValue,{"Attribute.2"}),
GroupRows = Table.Group(ReplaceValue, {"Closing Store #", "Final Store Closure Date", "Reporting Week", "Change in Status", "Attribute.1"}, {{"grp", each _, type table [#"Closing Store #"=number, Final Store Closure Date=nullable date, Reporting Week=nullable date, Change in Status=text, Attribute.1=nullable text, Attribute.2=text, Value=number]}}),
InvokedFunction = Table.AddColumn(GroupRows, "fnStuff", each ((tbl)=> Table.Pivot(tbl, List.Distinct(tbl[Attribute.2]), "Attribute.2", "Value"))([grp])),
RemoveColumns = Table.RemoveColumns(InvokedFunction,{"grp", "Attribute.1"}),
ExpandedFn = Table.ExpandTableColumn(RemoveColumns, "fnStuff", {"Recieving store#", "BASE Volume", "Added Volume"})
in
ExpandedFn

Link to workbook: https://app.box.com/s/aj3o10p4mun9nxmlszcyvwn970hqwhzx