Bad customer service from pnp management

For years and years I have been shopping at pick n Pay and the service I was given today is really disgusting. Pick n pay has a weekend special with their Pampers for R110. 00. I get there is a no stock sign. I asked for a rain check I'm being told thy don't give rain checks on weekend specials and black Friday. I've been stock piling whenever pick n pay has specials and never or anywhere in their adds does it say no rain checks on specials. I am on my last trimester of my pregnancy and for me to travel till there and be handled the way I was handle is uncalled for. The manager then refused to speak to me walking away saying another truck is coming in later not knowing what time the truck will arrive. I want my rain check for tthe 2 packs of Pampers making use of the raincheck policy u guys have. It's not something I invented its always been this way. Please get back to me as soon as possible. This happened at Pick n Pay liberty Promenade Mitchells Plain.