Hi justsaying
There are a few points to tackle here, but generally speaking there is no law which states that something must be finished to a ‘high standard’ as that isn’t really measurable and is highly subjective based on the amount paid, the individual’s expectations, promises made and so on. Therefore, the EC is not obliged to adhere to a non-existant law.
That said, the builder, regardless of what was contained within the quote is responsible to ensure that the work is carried out to code and that usually entails Australian standards for workmanship and product specification. A solictor would make the assumption that work carried out is ‘to code’ and leave the rest to the parties to sort out rather than stipluating the quality of the work (unless that was the cause for using the solicitor in the firts place).
If it is quoted that ‘X’ will be done with the drain, and ‘X’ is in fact to code without specifying what is to be done with the rest of the job (or vague words such as ‘repair/replace surrounding tiles’ rather than ‘make good existing surface with matching tiles’) then you may in fact need to obtain a new quote to get this job done.
If, as you say, the drain is higher than the surface, then it is unlikely to be to code. If you used a licensed builder then their work will have a warranty. Get them back to fix the drain: maybe they will repair the tiles/pavers to your satisfaction while they are at it, but you will likely have to pay for materials as it doesn’t sound like that formed part of the initial quote.