Hi George,
I am surprised because we had two Polos and one exhaust failed at 8yr old and the other lasted slightly longer ,I was very impressed and had VW fit brand new OEM systems again then ended up selling both the cars to friends for there Daughters .
If I am honest though the aftermarket prices for non VAG pipes fitted were so similar to genuine it hardly seemed with buying a cheap aftermarket version, I think so many People/members have fitted Millteks etc you should be able to buy one here cheap enough
Hope you get it fixed