Immediately stop paying rent to the former owner - it is money down the drain.
If you have a valid lease, the bank must honor it. Otherwise, the bank must give you a 90-day notice. Contact the bank to determine whether they have a "cash for keys" program. Some banks will create an agreement to continue your tenancy - look into it.
The new owner (even if it is a bank) must maintain your utility service. Civil Code Section 1950.5(l) requires the landlord to either transfer the remainder of the security deposit to the new owner or return the remainder of the deposit to the tenant.
Consider contacting a legal aid organization such as CRLA (they provide free landlord/tenant advice and advocacy if you are income-qualified). http://www.crla.org/
Ms. Farley provides an excellent response. The only additional information I can add is that you may have a cause of action against your prior landlord. Consult an attorney and do not hesitate to take your landlord to small claims if necessary.
The above is general legal analysis. It is not "legal advice" but analysis, and different lawyers may analyze this matter differently, especially if there are additional facts not reflected in the question. The above response does not create an attorney/client relationship. I am not your attorney until retained by a written retainer agreement signed by both of us. See also avvo.com terms and conditions item 9, incorporated as if it was reprinted here