Unhappy about out of stock

So me and my mom havea contract with telkom both it was a special for huawei nova with a power bank extra with. they said they will let us know when we can come ans collect the power bank one month later we go in still no power bank now all of the sudden my mom can maybe not get the power bank and she will get something else. so why do they advertise a huawei nova contract for R220 a month with a power bank and you get to the telkom store and still no power banks so why don't they order the power bank also the samsung should also get the power bank now they come up with excuses like the samsung get no power bank but thats not what the adverti*****t said so they make empty promises we just want our power bank after waiting a whole month now