Bad payroll experience to an ex employee

My name is Tshepiso Motaung, I worked for studio88 group for 6yrs as a store manager, they promised to promote me to be a regional manager but when I got pregnant 2017 things changed,going forward 2018 I went back to work they demoted me a assistant manager, 2019 April 2nd I resigned, they payed me R2100 said that's all, they don't owe me anything, OK I was fine. My recent job I got dismissed March 2021 I went to labour department they said I must go to studio88 group & get Resumption date from 2018 maternity from Blue falcon trading which is studio88, I call several times Hr & payroll they said they don't know what I'm talking about & I even emailed Candice young payroll manager she said she doesn't know what I'm talking about, I went back to labour department they said I won't get my money if the is no Resumption date from 2018 maternity they've asked for, please help me.