Deposit transfer across stems — confirm refund difference with owning rep

Client may pay deposit on stem A then switch product to stem B and ask refund of difference.
- Confirm which stem keeps the deposit credit.
- Confirm arithmetic (deposit − applied amount) with owning rep before BB refund.
- Ask refund destination banking only after amount confirmed; never export account numbers.
Example: TB4337-BRIANT-2 → TB4403-BRIANT-45; R5110 − R3927.25 = R1182.75 (batch 51).