Invalid voucher coupon offered

I was lured into registering an Takealot account as an FNB account holder, I received an email offering me a R250 voucher as a new customer using my FNB card, and spending a minimum of R550, I then searched on their the Takealot site and there was an item that cost about R688 so I decided to go for that one and everything went smoothly until I had to apply the R250 voucher..it lost internet reception the first time and the voucher was there and by the time I got back online and trying to complete the order and the voucher had disappeared. I tried applying the code again and again and the message I got stated that I had “reached the limit” now because it was on the 30th and that voucher would also expiring the 30th,I ended up giving up and pushing the order through without the voucher and paid a full amount of R688 for my order I emailed Takealot even before I received my delivery and I was told there was nothing they can do because I had already processed the order and the voucher had expired and would get another one. All I wanted was for them to re-credit me with that R250 voucher or refund me my R250 paid oth the order that would not take the voucher, because they won’t help me, I feel I was ****med into registering with a voucher they knew would give me problems, I don’t believe that voucher was legit to start with, I was sold a dream, all I want is my money back or another voucher that actually works