Engin seized under warranty, 5 weeks ago!!!

We have been buying Hyundai bakkies from Hyundai for the past 10 years. One of our bakkies engine seized, under warranty and Hyundai Roodepoort advised us that the engine will be replaced. This is approximately 5 (five) weeks later and the bakkie is still not working properly. Got it back yesterday and had to return it again this morning. They only advised us now that the diesel filter must be replaced and the warranty does not cover this. Why did they not advise us before placing the old filter back in to a new engine. Does that make sense. My husband spoke to the DP, Verdi who has been of no help whatsoever. When he was asked what about our loss of income for the past five weeks, he advised it is not claimable under the warranty. Bad service is apparently not a problem, it is the norm. We have been patient for far too long now. Now they only advised us today that we need to pay for the \data dot"on the engine as well"