I need help understanding affiliate programs?

I'm wanting to join an affiliate program, but my problem is this. Once I create a sale through my web site and a person places their order. When they receive the order there will be all types of brochures and receipts with the companies name and all return sales I will lose a commission on. Is there anyway besides on my site saying bookmark here that can help me? Are there any affiliate sites that act almost like a private label and will handle all sales and customer service under your name? I think a company that provided this service would be huge because all the affiliates doing all the work marketing want their return customers. Anyone with any info or opinions on this, please write.