It looks like for many businesses (including mine), the fee difference between PayPal and a merchant account is fairly small. Given that, what I really want is

It looks like for many businesses (including mine), the fee difference between PayPal and a merchant account is fairly small. Given that, what I really want is a service with: 1. a good API 2. good customer service neither of which PayPal has in my opinion (we've used PayPal for over a year). PayPal's API works fine most of the time, but occasionally it returns a 500 HTTP error on a successful charge. This has caused several customer problems for us, and we've taken the ridiculous step of considering a 500 error a success and manually following up in those cases. We've pretty much given up on trying to work with their customer support, and are looking for alternatives. Anyone have recommendations on service with a great customer support?