Unpleasant shopping experience in Mannings

Mannings used to be my favorite shop for beauty and health care items,
but I don't know why,
recently,
I am kind of losing faith of it.

Last time,
the advertisement in the shop said I can get an extra pack of tissue paper of selected product,
by the time I paid,
they told me it was out of stock -
but the poster and the sample of the gift was still there.

I didn't want to waste my time for argument in the late evening - at the closing hours,
thus paid and left.

Today,
the advertisement said that buying three health care items,
I can get a pack of product free,
at the end,
they told me the body cream lotion is not the health care item,
as there are many customers at my back,
I didn't want to argue with them,
annoying the other customers,
thus paid and left again.

I just don't like the way they treat customers,
still remember the owner of one shop I worked for long time ago,
the boss told me that we should treat our customers nice,
and keep the promise all the time!