What do i do in this case:

I have an amazon customer account from my number. I want to make an amazon seller account from the same number. It wont let me login stating that i already have a customer account. Do i need to delete that account first and then apply for seller account? If so, how long does the customer account closure take and do i need to wait for some time before applying for the seller account? Also, how long does the seller account verification take?

Your help would be appreciated, thanks.