Are you looking for potting soil or just plain one ?
Potting soil is available almost in all markets. Like carefour, family food center , lulu . You will also find potting soil in all the nurseries located in the vegetable market. This is where you will find the soil ( earth + sand) mixed as well.

I hope it helps. I keep great intrest in Gardening. So do share your garden piks with us :)