Is this carnapping, took & used my car without my consent?

Pls help me kung ano ang pwede ikaso at ano ang procedure?

I asked someone to oversee my house. Gave 2k for her service. While out of the country, she and her friends used my car almost everyday and worst drove it to BICOL. These usage is WITHOUT MY CONSENT. they took my car from my house anytime they pleases.
A day before i arrive phils, they returned my unit. I only found out these when i saw a gas receipt & watch my house cctv footage.

Since they used my car, it overheat. Now its cylinder head is damaged.
1)Where n how to file carnapping case? If it falls under carnepping case.
2)And who will shoulder this damage?
3) the incident happened between oct21 to nov 9, 2016. Can i still file the case today may 2017?

Up

1. it is not carnapping as the car is with you. if they have access to the key, it will be hard to prove that use is without your consent.
2. you can demand from them for the repairs.
3. not sure since it will depend on what you will file.

I forgot to mention, that the 4persons already ADMITTED that they indeed took n use my car without my prior consent. These are supported by my house cctv footages. & my car has cctv camera as well

Now, after their admission, id like to lodge a formal complain. All im asking is, is this still falls under carnapping case considering all the elements present?

You can file a complaint, yes. but i don't think it will be under carnapping. You can approach your local police precinct to advise what is the proper case to file.