How to get Correct Google Shopping Search Term Attribution

Can this software or another provide a report of conversions that includes the keyword searched by the customer that led to the Google Shopping ad click. For example, customer visits www.google.com/search?q=desktop and then clicks our ad and buys our desktop. What software is available that will tell us that the keyword was "desktop" that led to this conversion and all others that we got on our site? We need this information for calculating ACoS per keyword for Google Shopping ads. Google Shopping search term report is 100% inaccurate reporting keywords with 2 clicks produced 7 and 11 conversions and therefore we need a solution for this missing information.