Don’t assume that because a product has been bought in one country it cannot be repaired under guarantee and registered in another
Most , if not all companies operating around the world , have a double system of guarantees, one is called an international guarantee and another is operated by the local distributor, often a third party but sometime the same company although a local division.
Check which guarantee you received with your instrument.
Apple for example, honors an international guarantee, alongside the national one ( I have had experience with two items and as long as I contacted Apple , not just any store but their own official one, they were prepared to honor the international guarantee) similarly other companies do so (Nikon, Fuji and so on) , so first and foremost, read accurately the guarantee leaflet that the product came with, then get in touch with ROLAND USA and try to to get them, in writing, to admit (if applicable according to the conditions printed on the international guarantee) that there is indeed an international guarantee protection regardless of where the item was purchased.
This may very well be the case.
In many cases international guarantees are lasting longer while the international guarantee is limited to a period of 12 months.
Local Roland importers have 5 to 10 years guarantees on some products and may offer only one year to buyers of international items.