I am being audited for my 2017 form 1040 and i do not think i will be ble to provide them with the correct reciepts. what do i do?

[SweetieJean]

Unless you can reconstruct everything from bank or other records, be prepared to have the IRS deny or adjust your filing. 

[brainerdt]

What does that mean? Will I have to give them back the refund and pay a penalty or what?