REST API changing the price of an item on a referenced RMA does not work - orig order price is used.

Summary:

When creating a referenced RMA using Rest API we are not able to change the amount or price to something different like the below.

"ChargeCurrencyUnitPrice": -4.00, 

"ChargeCurrencyExtendedAmount": -4.00,

"HeaderCurrencyUnitPrice": -4.00,

"HeaderCurrencyExtendedAmount": -4.00,

When the referenced RMA is created it uses the prices/amount from the original sales order.

How can this be overriden?

Content (please ensure you mask any confidential information):

Here is an example payload:

{
"SourceTransactionSystem": "OPS",
"SourceTransactionNumber": "Credit_Only_ref_edirect_Pr2",
"SourceTransactionId": "Credit_Only_ref_edirect_Pr2",
"TransactionType": "Return",
"TransactionTypeCode": "SCCL_RMA",
"BuyingPartyNumber": "C4666",
"TransactionalCurrencyCode": "GBP",
"RequestingBusinessUnitName": "Supply Chain Coordination Limited (SCCL) BU",
"RequestedFulfillmentOrganizationCode": "EDIRECT",
"FreezePriceFlag": true,