Ouch, vora! I'm sorry to read that the experience converting your lines from an individual account to a business account didn't go as smoothly as we would have liked. I know that for both legal and security reasons, there are some information requirements for conversion, but it sounds like we didn't give you advance notice of the documentation we'd need? Am I understanding correctly based on your post that the requirements were more stringent because of how recently your business was opened (congratulations, by the way!)? That's valuable feedback, and we appreciate you taking the time to post here and let us know so that we can pass it along.
I don't think retail stores are equipped to set up business accounts.
When we changed over a few years ago from my personal name to an account in our business name:
They needed the Fed ID # (EIN) for the business. They waived any credit check because I guaranteed the account and had been a customer for years.
Business accounts are handled by a separate dept. Everything is done over the phone. Just call in and ask to speak to a business rep to set up an account. CS is also handled separately. I don't think there is a minimum number of lines required. We have 6 - but when switched account over from personal to business - had 4.
No personal contact. All done by phone and email.