Please could someone clarify this... 
How many times can I enter Thailand via land border per calendar year? Is there a limit to the amount of land crossings one can do, regardless of the visa type?
I have entered the country through land borders twice this year, both on 30-day VOAs (exemptions). Of course I know I can only do two border runs per year for VOAs, but I've just been told I cannot cross a land border back into Thailand this year on a VALID VISA because I've already done two border runs this year.
 I've never heard anything about this. I even entered Thailand 3 or 4 times last year via land borders without any issues so I'm a bit confused. Have I missed something here? 

There is no limit to the number of entries by land you can do with a visa.

 

There is a limit of two entries per calendar year when entering visa exempt.

 

Avoid Poipet and Padang Besar.

Tim has already advised correctly. I'm not being picky, but just to advise...your 2 border entries were not visa on arrival. You entered visa exempt. Depending on history you can also enter via flight.

Edited July 9, 20196 yr by DrJack54