How to fix damaged marble tile

My wife accidentally cleaned the dirty grout of our bathroom floor with Ajax which has lactic acid and phosphoric acid... all the bad things for marble. We have marble/ceremic tile veneer(?).
There is now loss of the top coating on the marble and it has gone rough and has a permanent whitish stain on it (photo attached).

Does anyone know how I can fix this? Can I put sealer back on it?
Are there professionals that specialise in this type of repair job?
Is this fixable??

Thanks everyone. This is our PPOR.

 

Try asking at a tile shop maybe an old school tiler who will share a couple of tricks.
You could try putting some sealer in just those areas and build up a bit with couple of coats.
Not sure if it will be a complete success though.

 

Wives shouldn't be allowed to use such abrasive compounds - get a divorce.

Apply Ajax evenly to the rest of the floor