I had a new Armstrong Resort Tile placed on my floors. After the 24hour wait time, I noticed some grout on top of a few tiles. I have called the company several times but no one has showed up to take care of the problem. I have been reading on line articles, use vinegar, no don' t use vinegar it will make the grout yellow. I have tried to call the manufacturer who keeps referring me to the installer. Can you help?