Dispute = banned. It's a hardwired rule and it does not change. If for some reason you're positive your account is messed up you should contact a paypal representative by phone.

Remember that billing issues are NOT the responsibility of MSX. All we do is take the money paypal bills you. If you're charged for 2 subscriptions you'll have to call them and find out why.

But above all - do not file a dispute. You'll be permenantly banned from MSX, Mist, and the forums.