The rumbling noise you hear is it the drain pump running all the time?
If you open the door and pore a jug water in there and close the door again does it pump the water out?
Ok what has happened here is water has leaked into the base which has activated the flood switch which then keeps the pump running all the time. Thats why you cannot turn it off without unplugging it.
What you need to do is pull the dishwasher out and lean it 45 degs backwards and this will clear the water from the base so you will need a towel for that part.
Then stand it up right and retry it and see how it goes from there. Fingers crossed its a on off overfill that caused this.
But if it does it again then theres a leak under there which you need to find and fix to cure this. You need to remove both side panels and from there you can check the hoses and try and see were the leak is from.
Let me know how it goes.
No worries Tony.
Hopefully you will sort it.