That was no doubt noted on your passport records with immigration and enough for the immigration officer to take a closer look at your travel history and become suspicious you are not a genuine tourist.
One small mistake is all it takes..
I think your only option is to apply for a tourist visa before you try entering again..
If you cannot get one then consider Phnom Penh Cambodia as that's an interesting place to visit and long term visa are easier to get if you have money..
So what you are really saying you can stay as long as you like by using border runs for a long period of time but you trap yourself in Thailand because if you leave for any period of time there is a chance you will be refused entry if you try to return?
Doesn't sound very smart way to do things and as already pointed out also quite expensive.