Clearing the debt makes sense but be prepared for how long it would take. if you are contributing €500 at present, after tax you would have an extra €300pm to clear the debt. So how long would it take you to pay off the €8000 if you were using that €300 in addition to whatever payment you are now making? Both at the current rate of 17% or at a better rate if you get a cheaper loan to clear down the CC debt?
You may be looking at 2-3 years (I don't know what your current repayments are but I am guessing you are making some). Would your employer continue to contribute for that period allowing you to continue building your pension fund?
Needless to say but just in case, the first thing to do is to stop using the credit card completely.