take it back and say you came out in a rash (go in with no makeup on). Given the price of that range I would say you should ask for your money back. Also - they are a bit pseudo natural IMO, and you are better off with Liz Earle or Sanctuary at Boots or even Soap and Glory
Agree with margherita - IMO L'Occitane is more of a marketing concept than a serious 'natural' (as much as anything can be - even plants are made up of chemicals) product. I've also always found their perfumes very strong and 'artificial' smelling. Definitely take the product back and ask for a refund. I've done this with a v. pricy Lancome cream in past when I had a bad reaction and they refunded without fuss.
As for what is really more 'natural', as I've said, I think there's lots of hype around on that one, and I wouldn't particularly recommend another line on those grounds. Also, my own skin isn't oily so I don't know what works best.