Customer *******

I bought a LG TL WASH/M T1866NEHT2.ABMQESA BLK at Builders today at R11 899 just to later see that Makro is selling the EXACT same machine @ R10 999. It is at R900 difference - both normal priced, not on promotion. Both Makro and Builder are part of Massmart so please explain how this is possible?? This is day light *******!!!