@Paul *******
Slightly rude to reply that curtly to somebody who is trying to help, even if they misunderstood what you were trying to say.
To make sure everyone understands, we need you to clarify what you mean by "border run".
Standard terms are "border bounce" and "visa run". "Border bounce" means leaving the country and going straight back in, and "visa run" means crossing the border and going to a consulate or embassy in another country to apply for a new visa.
This is how I understand your situation. You used up your 60 day tourist visa and extended it by 30 days in country. Now you want to know how many days you will get if you cross the border and go straight back in - "border bounce".
The answer is you will get a 30 day permission to stay based on a "visa exempt stamp" IF your nationality qualifies for it.
Other conditions apply if you are not from a country that qualifies for a 30 day visa exempt stamp.