R50 Off False Advertising ***

They promise you R50 off when you do an online purchase, only for you to not get all the things you ordered and paid for,and then they tell you your Money was short,but how cause? when you done selecting what you buying the total comes and then you pay the total shown + extra rands (Total was R899,97 but pick and Pay reserved R905,72 on My bank Card). STOP FALSE ADVERTISING. Hope I will get My refund for the things i didn't get as promised.