A 240V wiring is a possibility. The amp can be wired for 100VAC, 120VAC, 200VAC, and 240VAC. If that were the case, a tech at Sweetwater might be able to configure it properly and decrease the turnaround time.
A quick thing that you can check is the back panel fuse. With a 120VAC amp, it should have a T4AH250V fuse; for 240VAC, it should have a T2AH250V fuse.
T is a slow-blo, 4A = 4 amp, H = high breaking capacity, 250V. Having the correct fuse for 120VAC doesn't mean that it is wired properly inside. Someone would have to look. I assume that you were given the proper line cord for 120VAC. But if there is a T2AH fuse in there, something is up.
A quick thing that you can check is the back panel fuse. With a 120VAC amp, it should have a T4AH250V fuse; for 240VAC, it should have a T2AH250V fuse.
T is a slow-blo, 4A = 4 amp, H = high breaking capacity, 250V. Having the correct fuse for 120VAC doesn't mean that it is wired properly inside. Someone would have to look. I assume that you were given the proper line cord for 120VAC. But if there is a T2AH fuse in there, something is up.