My R600 voucher disappeared

I place an order on Takealot for a set of pots , I was using a voucher of R600 to make payment . I added the voucher but did not complete the order , the following day I got an email from Takealot stating the order has been cancelled due to non payment . I started a new order , but I when i try to use my voucher i got an error that said maximum redemption limit reached . I sent them an email and I was asked to send screenshots of the error to which I sent to them , it has been 4 days now and I am not getting an response . My R600 voucher gone just like that ,