Personally, I'd return the starter and if you actually need a starter, buy it locally. Just avoid the cheap import starters sold by Autozone, Kragen, etc. No, their "lifetime warranties" don't mean they are high quality, they are not. The lifetime warranty is just a marketing gimmick since they know few people own their vehicles long enough after installing a new starter so it would cost them much.
I'll never buy anything like that over the internet, it's just easier to buy such things locally. That way, if there's a problem, it's far easier to resolve or exchange for one that fits.
When you have a choice, buy American.