Cannot purchase end walker

Every time I try to purchase end walker off the website it get a CVV error. Not sure what to do at this point. I was recommended to use a third party website but I'd rather not if possible. I've been trying since yesterday with no luck. Any advice would be appreciated. Cheers

just get it through steam. Unless you have the previous patches from elsewhere. In which case, well, forget I said anything..

What did you say? I forget.

lol yeah I don't think I can get it off steam unfortunately.