Hi, I'm Ashik. Welcome to JustAnswer. I'm reviewing your question now, and will post back with your reply ASAP
I'm sorry about the issue. Unfortunately, the contacts are not saved on folders like pictures and files. The contacts are stored in a special format where only your phone can read them. You computer will not see those files unless you exported the contacts to vCard or VCF file first. You will not be able to export the contacts now since you are not able to access the screen or phone.
If you had added your Gmail account on your phone, then there is a chance that the contacts are saved on Google. Go to this website and sign in to your Gmail account --> https://www.google.com/contacts/
If the contacts are backed up, then you will see them there. There is another way to get the contacts to the computer, it might not work since you are unable to open the phone, but I will send you instructions in a few minutes
Option 1 :
Try syncing the phone to your computer using LG Bridge app. Dowload it from here --> http://www.lg.com/hk_en/support/software-firmware?superCateId=CT20136017&categoryId=CT20136018&subCateId=CT20136022&modelNum=H815T&keyword=
Open LG Bridge app and connect your phone. If it recognize the phone, then it will allow you the sync phone to your computer including Contacts to Windows Contacts or Mac Addressbook if using Mac etc
Option 2 :
Download this application CopyTrans Contacts from here --> http://www.copytrans.net/download/
Open CopyTrans application and connect your phone to your computer. Does CopyTrans recognize the phone ? If so, then you will see your contacts there and it will allow you to export them to your computer. CopyTrans is a paid app. So please try the trial version first.
These application usually requires giving on screen permission from phone. So I can't guarantee it will work, but it is worth a try. Let me know how it goes please