Be skeptical of attorneys promising certain results. Airtight cases just don't exist. Request copies of all letters and documents prepared on your behalf. Don't sign any document or paper until you understand the full import of what you are signing. If you have a fee dispute with you lawyer, consider arbitration as an option.
Some bar associations provide free arbitration of fees.
If you find or suspect a lawyer's conduct to be unethical, you should make a complaint to the appropriate disciplinary agency by contacting your local bar association or the highest court in the state. The fifty state supreme courts may disbar, suspend, or censure a lawyer for unprofessional conduct. Under no circumstances should you feel it is necessary to continue to be represented by a lawyer once you have discharged him. But don't act hastily. Often a conference with the lawyer can ease your concerns.