What to do with deeply stained tiles?

[ReturntoSG 0]

I have tried scrubbing our bathroom floor tiles to remove years of dirt and stains that someone suggested has perhaps gone beyond the surface layer. 

It's not the whole floor but just a third of the area that needs replacing. Besides getting the tiles replaced, are there any other solutions I can try?  I have been told that I could use epoxy paint and paint over the tile. 

Anyway, can anyone kindly recommend a tiler or contractor who can take on a small job like this and help me? Small budget for this job.  

[bykaraanne 30]

Have you tried melamine sponge or bar keeper's friend? 

[ReturntoSG 0]

what's that and where would I find it in SG?

 

[jaiyerika 5]

Make a paste using 1 part vinegar 3 parts baking soda. Let it stay for a while o the tiles. Rinse with clean water