Kia Sportage 2007: Idle/rev problem

Fuel companies have warranties that provide cover in situations where poor fuel causes problems, but before you can even think about approaching the fuel company you need to establish that your problems are a result of poor fuel. You need to be able to identify the outlet you bought the fuel from, produce a receipt of some sort that verifies the purchase and then some evidence that proves the fuel was the culprit. I would certainly get another opinion.