Using approximate lookup and getting duplicate returned values

Book1.xlsx

I have two sets of data - one set has exact times that an order was touched. The other sheet has calls that came in and the time stamp of said calls. I have to take that call time stamp and use some sort of approximate lookup (either INDEX/MATCH, VLOOKUP, LOOKUP, etc) and return whatever time stamped order touch is closest to my contact time stamp. My issue that I am running into is that multiple order numbers are returned that are the same, which voids my results because each contact needs a unique order number. I wish there was a way to do an approximate lookup and include an IF function that did not allow duplicate values to be returned but I am coming up with nothing. I need multiple criterion for the lookup, one exact (agent that took the call/handled the order) and one approximate (time stamp). Can someone help me please?

I wanted to add - column B is what I am trying to fill in with data from the second set of data on that sheet.

Does anyone have any input on this?