SOAP Web Service to Assign a Responsibility to a Contact

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SOAP Web Service to Assign a Responsibility to a Contact

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Hi, does anyone know what's the best SOAP WebService to use to Assign a Responsibility to an Existing Contact?
I've already opened an SR on this to Oracle but the one they provided "mergeCustomerAccount", isn't really helpful. It has so much fields to populate and it isn't working properly when i tested it.

https://docs.oracle.com/en/cloud/saas/sales/18b/oesws/Trading-Community-Customer-Account-CustomerAccountService-svc-74.html

Any help would be appreciated.

Thank you!