Is there a way to get all the cost in a WIP Completion Return, in a non-standar job, of material who

The operation of my customer doesn't allow to make a BOM for all the manufactured items, so they only make a non-standar job with a BOM with only one item. In the materials Issue, they choose Specific Materials, and select the needs of the inventory.
The problem is when they find a mistake and they needed to return the assembly to the WIP. In this point the system takes the assembly only with the cost of the resources and the overheads, the cost of the materials is sending to the Cost Variance.
Is there a way to include all the costs to the value of the assembly returned to WIP?