Where to order a new transmission shifting cable?

So, we recently realized that the shifting cable on our truck was not going into park. So, when my boyfriend went down to look at it, he realized that the plastic piece had been snapped off somehow. Can you point me in the right direction as to where to order just the plastic pieces of the shifter cable? The cable itself looks like it's in good condition but we can't get the correct shifting aspect without the plastic pieces. Right now we just put the emergency brake on as park, but we know that's no good for the truck. Thank you in advance.