I've never had an issue with Purse.io, and there are also places where you can get Amazon giftcards/vouchers so you can redeem the cards on your own account. One such site I know of selling these vouchers is
Bitrefill.com, and I've bought a few hundred USD of Amazon GCs from them with no issues in the last few months. You can also request a discount of up to around 20% or so and get your order done in a reasonable amount of time, though the default rate Purse.io sets ensures your order gets processed as quickly as possible.