Unfulfilled order without free delivery offered on new order.

Used a voucher and ordered a 5L Biscuit Tub with it as it would then include free delivery. I was emailed that biscuit tub got lost in transit and I would receive a new one on 6 December. Shortly after that wthin same day received email that they cannot get another tub of biscuits and I now have credit. I now have to spend more money in order to get my free delivery. That I feel is unfair. Not impressed with Takealot and so far no one has bothered to answer my email that I sent to them regarding this.