7 day cooling off period failure

I took a vodacom contract out on the 6th of October and I was told that if there was an issue with the handset to return it within 7 days.

I returned to the store on the 10th of October as the voicenotes were unclear or silent when sent on watsapp. The store was closed for stocktaking purposes. When I returned the day after the technician wasn't at the store . I phoned the LG technician and explained the issue and said I wanted the contract voided and would return everything the day after he said he would be at the store. When I returned the technician was not there and the consultants told me to come back the next day as he needs to test the issue. The day after he was not in store and I was told that they needed the technician to test it and then send the handset to JHB for testing and if it was faulty they would replace it with another LG.

I was not very impressed as I have lost faith in the product and wanted to rather stick to Hauwei. I have 2 contracts with MTN and had no issues in many years. Really not happy about this ordeal!