The options say "Thursday" but vendredi is "Friday"...

Depuis is pronounced very poorly.

Can I say, "I didn't talk with my friend since Friday?" Not sure, but it was marked wrong.

I didn't speak to my friend since Friday - rejected.

OK, I know the solution is the common idom, but my solution means the same, and most phrases in the passé composé so far on Duolingo accept "didn't". Can we have some consistency ?

With since have/has should be used. It has been raining since yesterday. We can't say it rained since yesterday. So i didn't speak with my friend since Friday is not accepted.