Terminating employees according to article 120 of the labor law

Hello!

My private LLC company terminated my limited contract with them effective immediately (without any notice at all) last Wednesday, December 2, 2020, under the grounds that I have violated section E of Article 120.

Actually, they fired more or less than 13 people and most of us were about to finish our contracts January-April next year. As for me, my contract will end in February.

The thing is, our employer told us all that no one of us will receive our gratuity because of their allegation that we violated section E of Article 120.

The termination letters that they gave us have the heading of "Termination Notice" but on the body of the letter, it was written that our contracts with them were terminated on that day that we received them effective immediately.

Also, the name of the HR manager was not signed and they just wrote the first name and the first capital letter of the surname like "John D."

Please advise on how we should proceed. We would truly appreciate it.

Thank you!