I could never ever imagine, that Coursera will be very close to scammers! In short - I choose to enroll in course "Promote your Scientific Results" (i.e., my emplyer payed for the course). I submitted all the needed assignments, BUT... I can't get my final grade and certificate, because it depends on other students, who have paid for the course and who have reviewed my submissions! The Coursera's support team keep answering the same thing over and over - just wait. Month, year?