How to make our refrigerator door stay closed

It sounds like the top hinge isn't holding the fridge door up at the top. The lower shelf in the door may be hitting because the door is down too far on the bottom to close without lifting it up. Try taking the lower shelf out and see if perhaps it might help a little until you can find out why the door hinge isn't holding the door up, and if you can adjust it in a way that it will keep the door opening and closing right. Start online at the manufactures site and see if you can get a solution.

Replace the shelf if possible. Have you got Ice build up behind the shelf?

check into using a shim behind the bottom hinge to align the door and have it close properly.

Start by making sure the refrigerator is level and then replacing the hinge. Just a slight defect in the hinge can make the door hard to close.

Has the fridge been moved lately for cleaning or painting? it might not be level.

Sounds like the door hinges need adjustment. They don't all adjust the same way. If you have the owners manual it should have a troubleshooting section. If you don't have a manual check out repairclinic. Punch in the model number. The have schematics, repair guides, manuals, and sell parts for all appliances. It's my go to place.