How to withdraw the appeal

Hello everyone:
My T1E application was rejected and I made an appeal to the first-tier tribunal (immigration and asylum chamber), the hearing date in in November 2014. But I've decided to withdraw it and leave U.K soon due to family issue.

My previous visa was expired during the application.

I've informed the Home office and Tribunal by post. And contact regional case ownership unit's number : 02072380137 which is written on the rejection letter. But they said I need to contact "voluntary departures office" of Home office(03000040202 or 01217133269) to arrive the trip, there's never anyone answering.

My question is what's there email address? And I read that "voluntary departures" is for overstayers, and you will get 1-10 years ban afterwards, is that true? But in my case I'm doing everything on time, not overstaying.

Please advice.

@ hallowvip, you don't need to contact tribunal as your appeal will be automatically withdrawn once you leave the UK. You only need to call HO to arrange your passport collection which I understand might be given to you at the airport on your departure day.