The plumber came out with an auger to unclog the toilet on the main floor. It backed up again a few day later and overflowed. Then the renter called the next day and said the toilet upstairs backed up and overflowed. I called the plumber and he said it was too small of hole in the toilet and it would just happen. He said he would not guarantee the work any longer because of the small toilet holes.
The next day, today, they called again and the 3rd toilet upstairs ran over as well. They claim they did not stuff the toilets at all. I lived there for 10 years and they never ran over, thought they did get clogged sometimes.
The other drains (tubs, sinks, etc. ) are fine, so the plumber says it's not a clog to the main drain to the sewer. I have a call into the plumber again, so I want to be a little prepared when he calls.