SC - Contract and vendor information disappear afeter change plant

Dear friends,

I'm using SRM 5.5 and i have the follow problem:

I create a SC using a item registered in MDM 2.0 the item has contract information and vendor information, but there is not information about plant.

The SC get the contract and vendor information but i need sometimes change the plant and when a change the plant the information about catalog and vendor disappear.

I tried use the BADI BBP_SOS_BADI to recover contract and vendor information, but in this moment i don't have how to get contract information because the catalog information disappear.

I'm using the classic scenario so i don't create contract in SRM just in backend System.

Thanks.

Roberto Aran.