Blame con artists if the Shoprite stores in Pimville and Zola in Soweto won't accept your cash.
The outlets are the only Shoprite shops in South Africa that will not accept old banknotes signed by former governor of the Reserve Bank Chris Stals, which were circulated between the 1980s and the late 1990s.
These supermarkets will only accept crisp new banknotes signed by Tito Mboweni, the bank's current governor.
Zola Maledu, the manager of Shoprite in Zola, says his branch has taken a pounding from counterfeiters over the past financial year.
He says all Shoprite's branches follow strict conditions for accepting banknotes. But a quick survey found no other branches in the country that rejected the often counterfeited old banknotes.
And what Shoprite's Soweto branches are doing is illegal, says Reserve Bank spokesperson Sam Henkeman. By law businesses have to accept any legitimate banknotes a customer might tender.
Henkeman says only the Reserve Bank is allowed to take old banknotes out of circulation.
Sipho "Hotstix" Mabuse, a customer at Shoprite in Pimville Square, says: "The elderly are being turned away with their savings and told to exchange their old money for newer notes at a bank."
He says the store refuses to take the banknotes even from old people who come in to buy food.
Though Shoprite turns away many people each day, Mabuse says, there are no signs in the shops explaining the policy to customers.
Stembiso Mbatha, Shoprite's manager in Pimville, says he is only following instructions from head office and is not allowed to comment on policy.
Sowetan reporters were turned away from the Shoprite in Pimville when we tried to buy goods with old banknotes.
But the cashier in Zola seemed so desperate to get away from of our cameras she did not inspect the signatures on the banknotes closely.
But her manager was seen refusing a R200 note tendered by a customer at a nearby till.
Brian Weyers, Shoprite's spokesperson, says the outlets have experienced many problems with fake R200 notes.
"Pimville and Zola are hot spots for counterfeit ban-notes, which is probably why those supermarkets are taking precautions," Weyers says.
"We cannot say that we do not accept any kind of legitimate notes as our business is 90percent cash.
"We will definitely lose a lot of money if this carries on."
Weyers apologises to customers for the inconvenience and says he will try to correct the policy as soon as possible.