Contracts as Prepaid blocks of time

Contracts as Prepaid blocks of time

Does the Zoho Support tool or any other Zoho product support prepaid blocks of time.

For example if a client purchases 10 hours of support services, then we would like to deduct time used from that block of time.  Then as the time is exhausted, or more accurately at a predetermined level, notify a staff member and possibly the client of the expiration (contract would have a predetermined expiration date) or exhaustion (for example, time is at 10% of total remaining).

We use ZohoCRM and would like this feature to be available in CRM as well as Support.

Thanks for the assist.