chances of getting back lost/stolen iphone?

so my iphone 5 got stolen abt 3 weeks ago.

soon as I realized it's lost I logged in to my icloud account to track my device using find my iphone,

but my phone appeared offline (probably turned off).

I put my phone on lost mode immediately, I also submit my contact number to notify me if my phone is turned on again and activated the 'activition lock'.

I didn't even have the thought of chances of getting it back since it's likely impossible.

but last night I received a SMS from foreign number (+9198xxxxxxxxx) claiming to be the icloud management saying that my iphone has been locked by icloud and someone tempted to login with another email. they asked me to verify my email account I use for my icloud and send them an email to idregister@icloud.com and if it matches with the email on my phone the device will be locked permanently.

so I did submit my email (only email, they didn't ask for password)

few minutes later I got both SMS and email reply from them. it is said on the email that my phone is currently in my local apple authorised service provider

(authorised distributor in my country which I bought my iphone from) and that someone took it there for service with reason "can't activate".

it's written that if I want my device back I need to remove my device from my icloud account to proof that my account has made lost mode for the device.

after that I need to send another email with the draft as following:

Subject : Device Remove

iPhone 5 16GB White

Imei: *******************

Serial Number : C**************

Email :***********

Identity

ID no :

Name :

Place of Birth :

Date of Birthday :

Address :

Country :

Phone Number :

Apple Authorized Service Provider near with your location :

at the bottom lines of the email said: "

After we get this email, we will contact you to meet some staff from Apple and

you must bring original box from this iPhone or bring your identity card.

If 1 x 24 hours we not get your email and you not remove that device from iCloud

We will give report to Apple Authorized Service Centre to open this lock.

We will not contact you anymore with reason this iPhone already sold and not lost."

so I filled in the identity field and again sent it to idregister@icloud.com. they replied that they will contact me shortly.

but now i'm wondering is this for real? or it's just some hacker messing with me trying to unlock my phone with the information I give.

but I think it's unlikely because on the first email from them they ensured if it really is my phone, they give all information about my iphone, including the imei,

my device serial number, even the date I purchased my phone and my warranty expiry date.

what do you people think? I need ur opinion. thanks!