I'm not sure you have any options.

Normally, snaking the drain is THE answer. If you can't get a snake through because of an obstruction, or a special trap, or such you may have to find a cleanout or take apart the drain.

BTW: I hope this isn't the same crew who used the chemicals. Most plumbers who know what they are doing would not use acid - which is what ate up your tub - ever to open a clogged drain. Call in a smarter crew.

Hi, Did the snake stop or did it go down the drain?I presume they snaked through the overflow. Look down the drain in the tub and see if their is any hair in the shoe. I have seen blockage in the short pipe that connects to the overflow.
Good Luck Woodbutcher

the "plumber" who loused up the tub is long gone..they did snake thru the overflow..
taking apart the drain? will pass it on..thanks

We need to know about how far the snake went into the drain.
What diameter was the snake used?