Incorrect SARS TAX Submission Code

I cannot submit my SARS Tax Return since 2019 as apparently Sentinel submitted the payment made to me under to SARS under the incorrect code "3920". I have been asking Sentinel to change it to the Source Code 3915 or 3901 to allow for my SARS submission. Sentinel informs me that they submitted it under the correct code "3920" that was issued by SARS and I inform them that SARS wants the code changed and Sentinel never wants to change the code. Why can't the code just simply be changed to allow for my submission and finalisation of the matter?