VW Motor Parts

Ordered a service kit for my VW, turns out that air filter was for a different model, once I contacted them they sent me a correct one very quickly and I sent them back the incorrect one. They were supposed to refund me a postage, it took them 2 weeks to do it and then they sent me the net amount. To my enquires why I was not refunded the whole postage, I had no response.I had to drive 12 miles return trip to get the incorrect filter posted back to them (they never offered to refund me the cost of petrol and had no response once I asked for it and I only asked for it when they refunded me the wrong amount).So on one side they responded well and quickly to get the correct product sent to me, but on the other you cannot trust them with refunds and they stop responding once in their heads they consider the matter closed.The amount was small in my case and they might think it is not worth it, but it is a matter of principle and it is due to their errors, so not happy with their customer service, will not buy from them again, cannot be trusted.

Used their ebay, very helpful, told me the exact engine oil I needed, very good price and it arrived the next day!

Bought 5 liters of oil online. No sales receipt/ invoice was supplied with the goods. Despite numerous emails and phone calls to their parts dept and accounts dept, they would not supply an invoice/sales receipt.is this some kind of tax fiddle they have going?