Is it possible to receive a prorated refund on my AppleCare+ as my iPhone was stolen and I can’t get it replaced

If you bought plain AppleCare - without Theft and Loss Insurance – all that it covers is things going wrong with the phone, and some forms of accidental damage (with a deductible). You aren't eligible to receive any money for the theft or loss of your phone.

You could check your homeowner's or renter's insurance to see if it provides any coverage. (I doubt it, but you can check just to be sure you're not overlooking something.)

I'm already using find my phone

What is the message that you see when you use Find My? Is the message "No Device Found" or "Offline"?

If the message is "No Device Found", then Find My was not enabled on the phone....before.....it was lost. So, it will not be possible to locate the phone online.

If the message is "Offline" this means that one or more of the following has occurred:

• The battery has run down
• The phone was powered off
• The phone does not have an Internet connection where it is currently located

Unfortunately, all that you can do is keep checking a few times each day to see if status of the phone has changed.

Since the phone was not covered by theft or loss insurance, I'm sorry but you will receive no compensation for the phone and you will have to buy another phone.

Hello! I am sorry to hear this, but I think that the only option you have is to try to locate your phone using find my app. It will really bad if you haven't turned it on, on your stolen device. Try to put your Apple ID and Password into the app. I don't think Apple Care supports stolen devices. The best option you have is try to locate your phone using find my, else you might need to go to an Apple Store and there you will be guided the best way.

Hope That Helps!