First of all what is this activation key for ? is it for the CService Username, cause if so it would have been better to place this topic in the CService Section, if it's for something else like mIRC registration or a softwear just mention what it's for and somebody might be able to help you.
Assuming you had a problem with they Activation Key for the CService Username...just try to register your username again within 24 hours from your last try, should work.Good Luck !
Regards,