When purchasing equipment for sole proprietorship, some items returned/exchanged. Do I include cost in date A and discount on date B when returned or leave out?

I purchased equipment (e.g. computer monitors, printer, etc) on several dates in 2017. On some of the earlier purchases, I found I had purchased incorrect items for my needs or found better items and returned/exchanged earlier purchases. The business expense / other common business expenses screen in TurboTax includes the date and comments (what was purchased). Do I put in the full amount on, for example, the first purchase date, and note the return (negative amount) on another line at the later date, or do I note the amount on the first purchase date less the amount of equipment that was later returned or exchanged?