Returning value if there is a difference

Hi all

"In cell M7 I would need a formula to say if Cell M4 does not equal 0 then return the film, country and Product name of where the difference is"

I have a issue with a reconciliation file that I thought should be simple, I have tried using some Index Match array's but have been unsucessful so far.

I have attached a "small sample" in the workbook.

I have a bunch of films in column B
a Country, US, & Canada in column A (there would be a lot more) the films repeat
A product code in column C
and the amount sold in column D

Then the same information from another source file in colums G-J

In cell M4 there is a calculation to see if there is a difference between the two totals in row 30

In cell M7 I would need a formula to say if Cell M4 does not equal 0 then return the film, country and Product name of where the difference is.

Is there a way to return multiple differences, right now the difference lies in row 4, but if there was a difference in row 20 and row 29 also?

Any help anyone can provide would be so amazing! I will as always try in the meantime!