Is it a fiberglass unit?
Is the hole in the wall or base?
If a unit- warranty should be at least 12 months.
The manufacturers warranty starts the day
the builder purchased the unit.
Often the retailer of the shower units have a repair
person which applies fiberglass or plastic patches.
This is a common problem. Especially of poor installation
practices and cheap units.
You need to get this fixed asap. Depending where the
hole is located you may get water damage.