Can I get a 7-day extension on my non-B multiple entry visa instead of doing a border run?

Hello.

I'm on a non-B multiple entry visa.

My 90 days stamp expires on the 26th May, but I fly out of Bangkok for a holiday on the 2nd June.

I would rather not have to go do a border run to Malaysia if possible.

I heard that I can get a kind of 7 days extension if I go to an immigration office.

Is that right?

Thank you!