Another who doesn't distinguish between 'touch' and scratch or dent? I may well have parked next to you, and even touched your car, but you would never have known as there would be no mark at all.
If they've left you a foot or less to get in, it's not possible to avoid contact. So many Chelsea tractors these days (I don't have one, by the way) and two of those can't park in adjacent bays without doors touching. So, either find somewhere with extra wide parking spaces or live with it. Of...
In some supermarkets - or other car parks - there isn't much space. Even more so in some of the older motorway service stations where the car parks were laid out when cars were much smaller than they are now - you can't get out of a car without the door touching the car next to you. Fact of life...