Reverse a cancel of an invoice

Hi y'all,

I have a serious problem over here with that SAP program...

I've done an invoice which later I've canceled it by mistake..... The BIG problem is that the invoice has already been given to customer and registered by that in their accounting departament....

I want to reverse the cancel procedure....

Both the invoice the and the cancel invoice has accounting documents with them.

can someone help me with that PLEASE!!!!

thanks a lot