I have asked them to replace the grout at their cost inc labour and topps are now making all sorts of excuses. I have said they are the experts so should have provided me with the best tools for the job as this grout has scratched the chrome mosaic tiles also
I was going to say actually, your size of tile would suggest it's ceramic, and could be a gloss finish. Topps shouldn't be supplying you with micromax if they are also supplying you with gloss, glass, metalic or any tile that has a shinny finish. It will scratch.
Standard Bal grout would of be suitable for what your describing and considerably cheaper than micromax.
Could you possibly upload a picture. There's been a few suggestions of what might be the problem. I think a picture would enable us to be pretty accurate so you've got something you can go back and tackle topps with.
The guys in my local topps are quite knowledgeable, but that being said, they are still sales advisors and not professional tilers. Did you fix yourself, or did you emply a tiler. If the later, did your tiler not question the grout choice on the scratching issue alone?