After 8 years, I don't think that it is advisable to ask for a replacement or a refund. Alas, hindsight is 20/20, but in the future, I recommend against purchasing solid wood furniture unless you REALLY trust the dealer. In my view, quality furniture and Indonesian furniture are for the most part mutually exclusive categories, so I wouldn't place the dealer who you purchased your items from among the dealers that you should trust. Many cabinetmakers offer MDF furniture, since it never warps, splits, or cracks. ALL solid wood warps, splits, and cracks over time, but if it only takes 1 year to do so, then the cabinetmaker is using the wrong moisture content for their wood.

I second what he said. For everyone's benefit I would like to see some pictures of the splits. And if they repair them ever the repairs as well.
Curious, what part of the country do you live in, any humidity issues in your home? Mine for example ranges from 30ish to (yikes!) I think almost 60 in the summer here in the Midwest.

The mass producers love their veneers and mdf for a good reason.
This stuff is just for fun, but

Curiously I have had no troubles with box store supplied oak and pine splitting on end tables I have made. Them wall clocks out of real tree pancake slices sure do like to split on me though. Thank goodness I work slow so it usually happens before I get a finished product.

Indonesia is a very tropical, humid environment, so it is almost impossible to build solid wood furniture their with out moisture content issues. If the furniture never left Indonesia then checking (splits or cracks) would not occur. But when this furniture is shipped northward to a much colder and drier climate, checking will occur. Its very critical that you maintain during the winter months a moisture level in your home, at no less than 35%; 45 to 50% should prevent any checking in solid wood furniture and some veneers also.