Goods on special and not available at the store as advertised

Hi i have been to pick n pay Mulbatton johannesburg just today again for their weekly specials advertised in the southern courier newspaper and once again i have a huge dissappointment They advertise hamper on special and when you to the stote to purchase these hamper they either out of stock or say that there was a misprint on the newspaper etc Baring in my mind that i go to the store only once the specials have start like if its says it starts on the 5th then i go on the 5th however this month i decided to go two days later allowing them to have stick allocated for the special as to may disamay the same story happened the oil advertised is a 5lt ans when u get to the till they say its not the 5lt but a 4lt so in actual fact this false adveri*****t by pick n pay Mulbarton and also that if you advertise specials as to my knowlegde then stock should be adequatly available I as a consumer and frequent buyer at pick n pay Mulbarton would like complain because this has not happened once nor twice but is an ongoing thing now and dont feel it right for me to keep fighting at the store for things that are advertised Thus what i am saying that this is unacceptable and that pick n pay as a retail company should investigate this and give me feedback and a apology in some way because this is not my first experience at the store