Hi,
Even it happen with me too, i had credit cards from HSBC they just kill me anyhw i manage to pay all amount and cancelled the cards, Now i have personal loan with HSBC last year they increase my installment payment when i ask them Y they inform me when i took loan it was floating interest not flat interest i ask no one inform me while taking loan anyhw. I think we cant raise our voice against them coz when we took loan they had made us to sign agreement which we dont read carefully so thats Y its HARAM in islam to pay and take interest coz its hert lot when bank force us to pay interest May ALLAH s.w.t. forgive us.....
Thx for raising this Q here...