MAKING SURE ACCOUNTS LINK

I couldn't sign on to my account to order my ink cartridges for my printer. It wasn't recognizing me.

My email server recently changed my email domain so I created a new account with Dell to order from. I have had a financial account with Dell for a long time. I want to make  sure that my new orders are linked to my original credit account. How do I do this or to whom shall I call to achieve this. A telephone number would be appreciated.