Filming the phones dropping scene (First day of filming)

Today, we filmed our first scene. It was the scene were Sarah is walking very quickly and drops her phone. This scene was hard to film as it was rapidly getting darker. Another problem was the damage that was made to the phone. As we had to shoot the scene were she drops the phone so many times, it seemed easier to put a case on it.
We then shot the scene were Nicholas (Stalker), had to call Sarah and tell her that he has her phone. However, we came across one issue; Nicholas said "meet me in 20 minutes", when he was supposed to say "meet me tomorrow"