AEG Competance Oven Door Doesn't Shut Properly?

Hello All;
Recently purchased a house and the first day we walk in the oven is broken and I am trying to deal with the estate agent who sold it to me and is non-responsive and uncontactable.
The hinge part of the door is very stiff on both sides and when you go to shut the oven door it is much higher up on the left side than the right and doesn't close properly.
Any thoughts as to why this maybe and if one can just fix this themselves?

Thanks,

Stephanie