Wont replace or fix vacuum cleaner under warranty

I bought a WD3 vacuum cleaner on 9 August. The motor started making weird noises and immediately phoned Head office who said I should take it in to the Edenvale Service Centre for an assessment as it was still under warranty.

I took it in on 18 July after speaking to the lady from the Call Centre. She asked if we used the bag and filter of which I rep**** yes, and then also took a picture of it before I sent it in.

I waited a month for the assessment, with hardly any feedback, and now they want me to pay for a new machine, and listed the problem that I did not use a filter bag, of which I did and have proof of.

How am I being charged for a new machine if it was still under warranty? They come up with excuses not to fix it, and put the blame on the customer. I should not be paying for anything, the machine needs to be fixed at no cost to me or replaced.

They just want to fit the bill towards the customer, and the vacuum cleaner was still under the warranty period when I handed it in for an assessment,