Date Field being split in Pivot Tables

I am encountering problems with Pivot Tables not maintaining the Date Format as it appears in the sheet I am pivoting. For example, my old version of excel may have a report containing data for the 6 month period ending in June or December, this would be shown in one cell on my report as either "Jun-2017" or "Dec-2017 (or sometimes as "30-Jun-2017" and "31-Dec-2017". If pivoting this data by period the pivot used to present the Date in one cell (just as it is shown on my report). Now, since a change in laptop and updated version of excel, my pivot wants to break the date into parts and I need the date to be reflected in my Pivot Table just as it is in my report (in one cell).

Any ideas on how I can make my pivot tables maintain the date in one cell, just as it is shown in my report? Formatting cells has been tried and this has not resolved the problem.

Your help is much appreciated.

Thanks
Wendy