No, you didn't. What a great opportunity to practice your French!
Well, we speak in English, but I have started to pay attention to the funny things he says like "I work in this company since 3 years" and I'm learning some French grammar by listening to him.
That's mean! But what an excellent idea. This is perhaps the one thing in French that is actually easier than in English!
point in time:
I have been waiting for my friend since noon.
period of time:
I have been waiting for my friend for two hours.
In French:
1. We just say depuis! Regardless of whether it's about a particular point in time or a period of time.
2. We use the present tense.