These days, when a credit card issuer decides that it no longer wants your business and decides to close your account, it’s not that unusual. When the issuer chooses to close your account without any warning, that (fortunately) is unusual and frankly, a poor business practice. Yet according to this AP story, that is precisely what Citi did to a number of card holders of its oil partner co-branded MasterCard accounts, including Shell, Citgo, ExxonMobil and Phillips 66-Conoco cards.

Citi allegedly closed many of these oil company affiliated credit cards last Wednesday, but did not send out notice to its affected cardholders that their accounts had been closed until the following Monday. Citi did not supply a reason for the account closures, though they do appear to still be accepting new applications for these cards.

If nothing else, the story once again underscores the importance of not relying on a single bank for your credit, given how quickly and unexpectedly it can be taken away.