Warranty dodging

I own a 2013 VW POLO 1.2 sedan that has completed 52000kms within the 5year warranty period. I have been told by them that the oil pump needs to be replaced which is highly unusual. This is such an unusual problem that they don't keep spare parts in the Western Cape. I was told I must pay R6800 first before they order the part. I asked why this was not a warranty matter and received no answer. I wrote to VW SA and again no response. So I have to conclude that the VW warranty is really not worth the paper it is written. My car has been regularly serviced at VW. Of course I have asked those who are qualified mechanics whether it is usual for an oil pump to need replacement under these conditions and in each case the answer was certainly not. VW shame on you!