Suspicious Marking practices

Inconsistent and suspicious marking of papers with unacceptable excuses. I had to resubmit a paper due to low marks. Originally i got 8/20 and 8/30. for 2 questions. With the resub, i added on and elaborated on my original ideas. When the resubmit came back, i got 0/20 and 0/30 for the same 2 questions. i understand a small variance but going from a mark to Zero. This makes no sense. I assumed it was due to 2 different markers having varying ideas only to log a query and find out its the same marker both times...so they disagreed with themselves? When i logged another complaint saying this is suspicious, i was basically told its due to myself using AI now suddenly?! How can a marker change their own marks so drastically. It costs a lot of money to reregister - which is what i will have to do as i am now not allowed to write the exam. I will be contacting the Ombudsman as this is highly suspicious in my opinion.