What is the ruling on working at Samba Bank as a telemarketing agent to offer credit cards and loans to clients? Is it forbidden in Sharia?

It is permissible to work in Islamic banks that do not deal with usury (riba) or prohibited transactions. It is forbidden to work in interest-based (ribawi) banks, because that falls under cooperating in sin and aggression. The Messenger of Allah, peace and blessings be upon him, "cursed the one who consumes usury, the one who pays it, the one who writes it down, and the two witnesses to it," and he said, "they are all alike." Allah has guaranteed lawful sustenance, and whoever abandons something for the sake of Allah, Allah will compensate him with something better.