If it was me, I would try diplomacy first with OC. Sometimes speaking to a manager calmly and explaining the problem is often a positive move. Tell them you had high hopes and are upset that the item does not do what you were led to believe it should have done from the description". Explain the steps you have taken, including their testing and say that you are still not satisfied and Infact you are very unhappy, which you clearly are.
I would think that for a card OC are not going to make too much of an issue over it especially when they have this huge forum.
If that approach does not provide you with satisfactory resolution then you have the option to write to the managing director, explain what has happened and say that the card is a) Not fit for the purpose it was advertised to do, b) Has not lasted a sufficient life span c) was sold with an inherent issue that you were not made aware of at the time of sales.
Sometimes persistence pays off. Be polite, calm but firm and in a lot of cases, being a pain in the butt to a stubborn supplier usually pays off because its cheaper to give you what you want than to keep paying their staff to constantly spend time dealing with you.
