Tribute Mastercard - First Bank Of Delaware ACCOUNT CANCELED BY THIS SHADY COMPANY!! Atlanta, Georgia

I have had an account with Tribute Mastercard (First Bank of Delaware) for 2 years.  I have ALWAYS made my payments on time, have had regular credit increases and only use about 15-20% of my available credit.
Today I went to Sears and tried to use my credit card.  It was declined.  Went to Wal Mart a little later and tried to use it again and it was declined.  I thought that was very odd.  I came home and looked my account up on the internet.  It shows that I have a balance of $214.00, $0.00 credit limit and $0.00 available credit.
I called the customer service number mad as all get out.  I get some dude that barely speaks English.  He proceeds to tell me that ALL Tribute accounts have been closed due to a decision by upper management.  I NEVER received a notice of this impending closure.  They even had the nerve to charge my account with the monthly maintenance fee for September.
Can they just cancel me like that??  What is that going to do to my credit??  We are working our way towards a mortgage this time next year and were told to have a mixture of credit lines.  Are there any other cards out there for someone like me?  My husband and I have been out of bankruptcy for 1 year.  We did not file on any credit cards.  We have credit scores in the upper 600's and have 2 vehicle loans theough our local credit union.