hi, i dont know what happens with regards to re-sitting exams etc but just wanted to say -you WILL pass! Im guessing you have your exam coming up as i was feeling like that before mine and couldnt sleep due to the worry of failing!
Best thing i can tell you is to try and relax, and when you have the exam try and put it out of your mind that its actually an exam! Keep telling yourself that its just the same as any other time you've done practical.
Well i can tell you what the policy is on it because there are times when people do not pass (although I hope that will not apply to you).
If you do not pass you are asked to re do the assessment NOT pay for a completely new class ... Good grief ... CND are not that type of people and do not have those types of policies!! They are there all the way to HELP you and encourage you to do your best.
When you are interested in a subject, generally you take in the knowledge you need to know. I wouldn't worry overmuch about it.