The difference in temperature between the boiling point of a solution and the boiling point of the pure solvent Concentration A measurement of the amount of solute that's dissolved in a given quantity of solvent; usually expressed as mol / L
If you get banned from Xbox Live, you more than likely deserved it barring the occasional name misunderstanding or misinterpretation that usually get cleared up quickly. Punishment can range from suspensions of 24 hours up to two weeks, on up to full permanent bans.
There are 7 days in a week. 21 days / 5 business days in a week = 4.2 standard weeks. It will take 4.2 weeks (30 days) for you to receive your xbox. It depends on how long they actually take to fix it (it is a maximum of 3 business weeks, it could take less time) wether you will get it back before christmas.