Service tax liability under reverse charge mechanism

Dear

We are receiving bill from Manpower supply agency. They are charging service tax on 100% value of their charges.

My questions are as per below:

1. As per service tax reverse charge mechanism should we are still lible to pay Service Tax on 75% of bill value.

2. For other services of reverse charge also if provider charge  service tax on 100% value, then we will be libale or not for receiver portion.

3. In case of man power supply if receiptent is not a company but the provider is individual, reverse charge mechanism will apply or not.

Thanks

Abhay