rusting after 5 months

We bought a Defy tumble dryer from Makro. The dryer is stored in a garage and is not used a lot. The other day when we wanted to use it we noticed that the machine had started rusting after only 5 months. We logged a call with Defy and they said that they would come out and then they did not. We followed up and eventually someone did come out after getting hold of Mr Morgan. The technician has looked at the dryer and now want s to replace the top of the dryer that was rusted. I spoke to Mercia yesterday and today at the call centre to say that we do not accept the solution and want the dryer replaced. It is only a matter of time before the rest starts rusting and then the warranty has expired and we are stuck with a machine that is worthless. She promised to phone back yesterday and that did not happen. I followed up today and she promised again to phone back. Again I was not phoned. Please resolve this matter by replacing the dryer. We will not accept any other resolution and will be forced to take matters further otherwise.