This is definitely not a cosmetic problem and unless properly repaired will not only continue, but it will probably get substantially worse. First, contact the warranty company (in writing) and tell them what's happening (include photos). Then, we suggest that you make an "structural repair". This is where a licensed structural engineer surveys the problem and designs a repair that will "hold permanently". He will probably suggest that you remove the vinyl and the tile flooring and the concrete slab beneath. The slab (and possibly some of the underlying substrate) is then replaced in accordance with the engineer's specifications. Following the engineer's advice to the letter is really important. Removing bad soil and replacing it with a proper substrate (compacted rock, loose grave, whatever) and then keying the new concrete to the old with steel bars epoxied into the old and protruding into the new are just of few of the things that will probably have to be done. By the way, the structural engineer will probably require you to provide a soils report. Often these are on file with the builder of the home or the local building department. If a cosmetic repair is all that is made there is an huge possibility that you'll be making the same repair again in a year or so.