Credit memo for terminated contract

Hi ,

WE have a contract which is terminated when the ownership is changed in Install base for the Item instance.

Ideally when contract is manually terminated ,once main billing program is run automatically SC will interface to AR for Credit memo but in this case contract is terminated when Item instance is changed with ownership .

Could you please help us now we want to generate the Credit memo for this terminated contract .When I try to submit this contract to main billing program its not interfacing.

Please advice any approach to generate Credit Memo for already terminated contract.If not option from Service Contract should we go ahead with manual Invoice