bought brake pads and they make noise when i stop

the beggining of december me and my mechanic we went to middas gezina because he told me that they sell good product. i bought wipers,brake pads and all he staff to service for yaris 2008 T1 as it was due for service .the guy who helped us its a black guy .well after the new brakepads were installed my car started making a ziiiing noise everytime i stop and it embarasses me every time i stop my car .i went to two mechanics and they told me my brakes are **** so i am very dissappointed with middas i want a full refund for those brakepads ,i dont have the box or the slip or il be happy if i can make exchange for a better products .