Just excuses

I went to Woolworths Edenglen on Wednesday the 25th of November, when i got home I realized they charged me for 3 bags of Ariel washing powder and i only took 2! The price was also R135 for 2 and they charged me R80 per bag??? I phoned the store and they just said i need to come back??? I asked if they can refund me and said the system doesn’t alow refunds???? They said i must send my bank confirmation letter with my ID to send it it head office! I send it immediately after they gave the e-mail adress and still haven’t received ANY response from them??? This is really pathetic that i need to struggle to get my money back! Woolworths inconvenience you and think just a sorry is acceptable! I want my money back and want compensation for the inconvenience caused!!!