Is it permissible to obtain a new loan from the bank to pay off an old loan, with the possibility of investing the remaining amount, knowing that the terms of the new loan are easier than the previous one?

The questioner's work in a usurious bank is forbidden (haram), and taking a usurious loan is even more forbidden (haram), as it falls under the curse pronounced upon the devourer of usury, its payer, its scribe, and its two witnesses. The questioner must repent to Allah and repay only the principal amount of the previous loan, for Allah Almighty says: (And if you repent, you may have your principal – [thus] you do no wrong, nor are you wronged).