Usually adjusting the oven hinges is a simple fix and this can be done by you, please see the below link on tips and tricks on how to adjust the oven door:

If you are unable to adjust this, or the adjustment does not help, please let us know as we can advise the cost of a technician to pop out.

Tips to prevent this happening again:
- Do not place dishes on the door (this can stress the hinges)
- Do not swing the door open/closed with force