Same problems as others are commenting on. They want you to pay up from, then they will bill your insurance, and when they are proven wrong then they will issue a reimbursement which takes anywhere from 3 days to 3 weeks (depending on you paid up front). Also the reimbursement process won't even start until you show them they were wrong and ask for the refund.
HORRIBLE customer service. If you want paid in advance or at time of service then submit the claim immeadl