INDEX & MATCH duplicate entry

Hi all,
I have a master Data sheet with a lot of information and what I need to do on monthly basis is to validate this data and cross reference it against what has been submitted by the 3rd party.
I have made a formula that searches, matches and returns the Data if its correct (refer to the attached excel file, column O and P) .

There is a catch though... some of the data have duplicate reference numbers (for example same docket numbers) and when i run the formula its unable to distinguish whether if its a double up and ultimately the formula reference the incorrect details.

Would you be able to assist me with a way to get around this?

Please note that I cannot modify and rename the docket names with the same reference numbers.

Many Thanks

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