Price fixing @ Kentucky fried chicken

Can someone from Kentucky fried chicken explain to me why they don't have fixed prices on instore and delivery services whereas we are paying for a delivery.

Yesterday I bought a Streetwise remix for R29,90 ,ten (10) zinger wings for R57,90 and today I bought from KFC Ga-Rankuwa through delivery services and boon prices are different Streetwise remix today is R34.90 and 10zinger wings is R69,90.

Is this not price fixing and it needs urgent attention.