What is the ruling on taking out a loan from a bank to pay the father for the "Shabaka" (bridal gift), knowing that bank loans are haram, and that not paying the amount to the father will lead to problems?

Borrowing from a bank with interest is precisely the forbidden usury (riba), and it is one of the major sins for which severe warnings have been issued in the Quran and Sunnah (definition). Therefore, you must repent to Allah Almighty with remorse and a firm resolve not to return to it. You are only required to repay the principal amount. If you can avoid paying the forbidden interest, then do so. Otherwise, pay it with the hope that Allah will pardon you. We advise you to be truthful, for whoever fears Allah — He will make for him a way out and provide for him from where he does not expect.