What Causes Pain In Knee After An Injury?

2 weeks ago i was told i ripped something in my knee, then i was told to use crutches and avoid putting pressure on it to wait for physio or last option, an operation. Now the hospital still hasnt contacted about physio, and they said they would up to 3 days after. And yesterday i experienced the crippling pain i had the first time. My knee is in agony, but i dont know wether i should be hassling the hospital about it or just putting up with it.