Q: Cant change the payment method in the payment information of my account

Recently I havn't been able to purchase anything, not even free items in the appstore, they say there is a problem with my payment method, I dont know what it is so I proceeded to deactivate the current payment method so I could download things again, but it seems rather imposible, since the option none, in the payment method of the payment info. in the view account information area of the settings isn't available, can't seem to do anything, couldn't get a hold of the apple call services, and I would like to update my apps already, it has been a while.

Thank you, please help