Regent Financial Services, a Tampa-based company you've never heard of, is so impressed with your responsible spending and timely credit-card payments that it wants to reward you with a gold Visa card. 'You've maintained an outstanding credit rating, and you deserve to move on up to a higher spending limit and lower interest,' the unfamiliar firm gushed in a mailing received by you Monday. 'Sign up today and 'Go Gold'!' A spokesman for you confirmed that you remain $8,000 in debt on your current Visa card. 