HOW LONG DOES IT TAKES TO RETURN MY PASSPORT.

[basgasbi]

Your appeal against our refusal decision has been reviewed and overturned by the Entry Clearance Manager. May we therefore take this opportunity to request your Passport.

Please send your passport to UK Visa Section using the address format shown below - this will avoid any delay in reaching us. We will return your Passport to you Via the DHL Courier Service. Therefore please provide your current Address.
This was the email i got from the visa section on the 10/03/2016.And i sent my passport to the UK visa section in Croydon as requested on that same day with speedpost (MRW)
BUT,am so worried as what is happening and how long is my passport going to be with them before returning it. Please, i need some advice on what to do. Thank you.
sorry i did't mention it that i live in Spain.