I haven't tried a Walmart warranty yet but it doesn't sound like a good idea if they don't even know the details.
I opted for a Squaretrade warranty on my Galaxy S III. They have 30% off codes on Tuesdays so it was a good deal. They have different tiers of coverage (one is up to $199 in coverage which would be what you'd want) but I'm not sure how much it costs. You should check it out.
I usually pass on these types of warranties but phones are getting pretty expensive these days!
Sent from my Galaxy S III
Castrol EDGE 0W-20 is my drug of choice.
Primary: iPhone 7 Plus, Galaxy Note 5, LG V20
Secondary: TracFones: iPhone 6s [AT&T] & iPhone 7 [Verizon]
Mobile Broadband: ZTE Z915 LTE hotspot (5GB for $10) + iPad Mini 4 w/ T-Mobile LTE