Tell them you will not be returning it and if they do take away your access you will pursuing legal action. Do you think you could ever convince them by saying

Tell them you will not be returning it and if they do take away your access you will pursuing legal action. Do you think you could ever convince them by saying hey I saw this domain was available but came back 2 days later and it's not available, can you still get it for me? The answer is unequivocally no. Know your right and defend them against overreach of private entities.