I removed your IMEI number to prevent someone else claim it to be their device and not yours.
You need to contact your Service Provider bcause they might be able to tell you wher ethe phone was when it was turned on. Also, if a finder or the thief is running up a large bill for calls and mobile data, you will be responsible to the provider to pay that bill.
When you buy another 'phone, install software that can allow it to be tracked. We can't help you any more here.
Contact the company now - it's important.