PNP ASAP double bills and accused clients of *****ing

On the 24th Jan I made a purchase of R1065 from PNP ASAP, they packed and delivered my groceries and then only to realize they double billed me, when I called in to query it they first said they dont know why i was doodle billed and will check the bill and get back to me. After holding on for 20 minutes on the call the lady Alex confirms iv been double billed and they will refund me which takes 3 to 5 working days, we ended the call thinking all was sorted, I then get a call back in 3mins stating that oh i was billed extra cause of variable on the beef stirfry meat i purchased which was 1 pack @ 57.00, she goes on saying the variably weight came to R960 hence i was billed extra yet my order shows its one pack of meat to the value of R57, she goes on asking me to send proof I only have 1 pack of meat, they basically accused me of *****ing meat and asking for a refund, until i asked them to call the store and investigate via cameras who packed the order and scanned will know the truth, after calling back like 5 times for an answer I get told so sorry for the inconvenience caused they actioning my refund and will offer me a R150 voucher with no explanation still no voucher handed to me like it will compensate their mistake, when i called back the next morning to find out the reason for the extra bill they advised their scanner was faulty and they charged me for over 10 packs of meat, I am livid with the treatment and accusation from PNP staff and what ****es me off they take our money with out letting us know and we must wait 5 days for a refund, whose going to pay my debit orders when im short money cause pnp asap staff do not know what they doing?????? disgusting I am taking this matter to the consumer ombudsman.