Oil question, VW 502 00 or VW 503 00
Hi I have a question, I cant choose which oil I should use in my Audi A3 2.0FSI -2004. The instruction book says that I should use only oils that meets specifications VW 503 00 or VW 503 01. But Castrol seller that I bout my oil from sold me 502 00 and when I checkt my instruction book in the car I whent back to the store but the seller told me that VW 502 00 is even better for my car (it is more expensive). The seller told me that the instruction book is out of date and the castrols recommendetions is more reliable. Is this true?
The seller sold me " Castrol Edge fullsyntetic 5W-30 " should I go back whit that one and change to " Castrol Edge fullsyntetic 0W-30 " VW 503 00?
ps. I want to change the oil in the engine not just refill.