They are being racist and wont pay my mom vacation?

so my mom works for value village savers here in Toronto...and the department is pure labor..lifting up stuff here and there..and shess noticed that her other employees got vacation with pay..n shes even got a certificate of working there for more than 5 years and as a good employee from the ...and now for the first time shes asking for vacation with pay.....and they are saying no to her and saying "now things have changed, thats why we dont pay for vacation"...they jus want to get rid of long term employees cuz employees that come from "employment centre" get payed less..which means more money in the supervisor's pocket...well i dont know exactly what they want..but my mom has known the supervisor since long ago..and she sees that jus cuz my mom is the same race as her...she treats my mom like dirt while being so nice to other employees and shes always picking on her allllllllllll the time..n she comes home n cries...im so pissed off at her racist supervisor...n my mom doest even say nething..its not the manager..its the supervisors that are f**ing around..and the manager is hardly there.. what should we do?