The only way to confirm that fermentation is complete is to check your wash with a hydrometer. If it is around 990 and has been stable for 2 consecutive days, fermentation is complete.
Bubbling is usually a good indication that fermentation is going strong, but should not be your sole indicator as CO2 gas might escape through other channels in your fermenter.
Before adding Turbo Clear, it is important that you have established with a hydrometer that fermentation is complete. It is also very important to add Parts A and B of the Turbo Clear, strictly 1 hour apart.
The most likely cause of poor clearing results are due to incomplete fermentation. You probably found it was difficult removing the gases at the end of fermentation prior to adding the finings. Always check that fermentation is complete with a hydrometer.
Leave it for a few days and it will probably clear on its own. It's fine to use more than one pack of Turbo Clear as this won't hurt the wash.