LIVES at RISK because Takealot will not take responsibility for emergency equipment it sold

Bought a new fire extinguisher in July 24 with a 6month guarantee. When it was received it had and retest date of August 24 on a label that had been stuck over a previous one. This label also detailed that it was sold in August 23. I presume that was to the supplier, certainly not to me. I returned it to Takealot as it was not fit for purpose and within its guarantee period. They say it does not qualify for a refund because their returns team had inspected it and say it is not faulty!!!! I ask did they test it? Are they qualified to test fire fighting equipment. It is a piece of emergency equipment, if it fails, lives of the whole apartment block could be in danger.