Call again, ask for supervisor (write down names of everyone you speak to), explain that you were not informed of any cancellation, why were the tickets cancelled (you don't actually care), and ask them to make it right to you by contacting Ethiopian and requesting the reissuing of the tickets that were cancelled without any explanation.

Also you might try to contact Ethiopian directly, ask for explanation and request that the fix the mess they caused.

Explain to anyone you speak to that this is unacceptable since you have already booked a few thousands euros of accomodation and domestic flights.

When is the journey?