OptumRx review: Incorrect billing and incompetency in correcting their mistake!

In August they billed me a $350 copay for my medication when they "forgot" to apply my copay assistance! My copay should be $00.00! After multiple contacts about this, reconciliation went nowhere! I then had to contact the copay assistance program MYSELF because they would not look into the matter enough to get it resolved! The copay assistance program rep called Optum directly to resolve the issue. They assured me it was resolved and I would receive a refund. I did receive a refund, but my account then showed a balance of $350.00. I spoke to a rep at Optum and they assured me I did not have a balance and they were waiting for copay assistance to pay and then the balance would disappear. Today I received an email from Optum saying a have a balance due of $350.00! This is a viscus cycle that no one at Optum will step up to the plate and correct! Today I was told I needed to contact the copay assistance program -- that's what I did three months ago! I have never experienced such POOR customer service or a company that literally does not equipt employees with problem resolution skills or ability. My insurance changed in October and I NO LONGER have to deal with their incompetency, but cannot get this issue from AUGUST resolved!