Unable to change mobile number because ID Number already registered. Really????????????????

Dear PNet,

Your system is NOT permitting changes to my Personal Information. I have NOT been successful in amending my Cellphone Number and neither my City and Province because, “This ID Number is already registered in our database. Please contact our support team for assistance: **********

The Mobile number on my PNet profile is wrong and should read: ********** 356. The City and Province should read “Vereeniging, Gauteng”. No changes to these fields are permitted because an error is returned: "This ID Number is already registered in our database. Please contact our support team for assistance: ********** I am fully aware that this ID Number is already registered in your database and that’s because I have previously registered it. I do NOT want to amend my ID number, merely my Mobile number, City and Province. I need to change the incorrect details, please. - See the previous emails sent to you, together with a screenshot of the error.