The Law -
It's not necessarily a conventionally accepted ethical practice- HOWEVER in the United States capitalism generally falls under the more commonly explained statement "Buyer beware". You have the opportunity to investigate and review everything prior to committing to purchase. This game is hosted and sold in the US. This makes it a US company and as such governed by US law. The BEST you could do is hope for sympathy from unregulated and unbiased resources (ie, the Better Business Bureau). I can tell you as an American Consumer who has been screwed and learned this is a part of life, it's a waste of time and you will get no sympathy. Furthermore, taking the recommendation provided above to "lie" to your CC company and charge back the purchase is fraudulent and 100% illegal. You (potentially) will become a "criminal" in the US subsequently getting you into much more trouble than you need. I don't believe 70 dollars would be considered an extraditable offense, but your cc company may have some ramifications as they want reciprocal business in the states. Ultimately, you're going to pay for it.
The best case scenario; you have learned a valuable lesson about conducting business - read all the information before committing to the purchase - ESPECIALLY the fine print. I highly recommend reading the Agreement
for a more comprehensive understanding of how the system works. Also, you should realize from the language, this has been written by an attorney and not some secretary. Unless you're a bajillionaire who can play the "Who can bankroll a lawsuit longer" and sue for the pure entertainment of it - you will lose this fight.
In any event this type of practice, long ago considered poor form is relatively common today in this country and therefore perfectly legal.
Summarily sir, you've been K2'd.
As a post-script, if my assumption is correct and you are in fact NOT American and your native tongue is not English, you do have slightly greater than a snowballs chance. Americans are ridiculous about common sense. Simply contact a lawyer and explain the website is not offered in your native language therefor not allowing you a complete opportunity to fully understand the terms of the Agreement. As a result you have suffered extreme duress from this revolting practice which does not occur in your country. (be able to prove that is true) You would like to sue the retailer for 100% of the purchase price and damages. If you have the capital (I would guess in the neighborhood of $100k-200k USD) you could set precedent in the supreme courts. Chances are you might find a lawyer hungry enough to "see what happens". It's marginal and you will likely settle out of court for the $70usd and 1/2 of total combined damages, maybe they'll throw in 5 grand to shut you up (yours + k2's, essentially you both cover your own costs, cause they'll counter sue for wrongful prosecution, maybe some manner of breach of agreement because your attorney will have you charge back your payments and force the issue with your bank) It's remotely possible, but frankly you would be better to let it go and be more careful from this point forward.
It's like the baby who touches the hot stove, it only takes 1 time to learn.. "Shit, that hurt. I'll never do THAT again"
Hope this helps answer your question
EDIT: If you ARE American, you're without hope of resolution. Lesson learned, move on. (The thought here would be you're a minor and therefore could not enter into agreement, but if you have a CC you are over 18 and could enter into contract. If you used your parents CC they should not allow you to use their CC unless they understand what they are buying.) Anyway you look at it.. sorry charlie.[/b]