I answered (thinking it was someone I knew in DE) - you get a recorded message saying that because you have good credit, press 1 for a special message. If you do, it turns out you get connected to a call center in India (or wherever) pushing Bank of America Credit cards. I demanded to know how he got this number since I am on the No Call list - he dared to try to tell me I am not! I told him if he didn't get me off this list I would report their skanky telemarketing behinds to the Attorney General. The Delaware number on your Caller ID does not accept incoming calls - hence the constant busy signal. Since I am on the No Call list, I'm thinking the only way they got my number (and most likely yours, too) is one of my / your credit card companies sold it to them.
This number was more than likely "spoofed" by foreign telemarketers. If it keeps calling you, file a complaint with the Federal Trade Commission. I did. They spoofed my old number. I finally had to change my number.