They sold you a road triple to replace a MTB triple (48/38/28 was a standard size to match freewheels, freehubs are often paired with 44/32/22 chainrings). Whether you'll have problems depends on what FD you have and if you can get the chainline worked out. 48/38/28 cranksets are still readily available so I wouldn't want the trouble of dealing with a road crankset.