Print out all emails and online bank statements that relate to the disputed charge. Save any snail-mail correspondence as well, and refer to it when you call or visit the bank.
State why you think the charge is unfair or unwarranted. Do your research before approaching the bank's representative.
Read the booklet you received when you opened your account and check the rules on the bank's website. Then check the banking rules for institutions in your particular state. Back up your complaints with facts.
Remain calm but firm when speaking with the bank's representative. Hold your ground and ask to speak to a manager if the first person you speak with can't resolve the problem.
Ask other bank customers if they have experienced the same excessive or incorrect charges. If other bank customers have endured the same problem, you will have better leverage when disputing your charge.
File a complaint about the bank with the Federal Reserve Board or your state's Department of Banking if the problem is still unresolved. This is a last resort.
Always contact another manager at the bank until you have spoken to every bank representative who is authorized to resolve the matter.