Roger Greenwood thought he had heard of every conceivable bank fee. Then he received his September credit card bill.

Bank of America charged the Jacksonville, Ill., man $39.23 in interest — on a $0 balance.

Greenwood was convinced it was a mistake. In August, he charged a vacation rental to his credit card, resulting in a $5,734.13 balance. Weeks later, he received $1,450 in credits from two merchants, lowering his balance to $4,284.13.

He paid the remainder of what he owed with an electronic transfer Sept. 6, three days before it was due, bringing his balance to zero.

His statement clearly showed that between the credits and his payment, Greenwood paid off the entire $5,734.13.

So why, he wondered, had he been charged interest?

Greenwood emailed Bank of America, and quickly received a response. An online representative agreed that between the credits and his Sept. 6 payment, Greenwood had paid his balance in full.

"However, we need to inform you that credits are not considered as payments on credit accounts," the representative wrote. "Therefore, the credits (of $1,450) were not considered as payments on this account, and the interest charges were applied correctly."

The representative told Greenwood Bank of America would not erase the $39.23 in interest.

"We regret we are unable to remove the interest charges at this time," the representative said. "Therefore, this transaction will remain part of your account balance."

Greenwood emailed Bank of America again and received the same reply from a different representative — the $1,450 in credits weren't considered payments, and thus he was charged interest on that amount.

Flummoxed, Greenwood emailed What's Your Problem?

He said he simply couldn't understand why he was charged interest on a $0 balance.

"I don't know how they can even justify it really," he said.

By Greenwood's accounting, he would have had to overpay his balance by $1,450 to avoid the interest charge. That, he said, was just plain goofy.

"I can't fathom it," he said.

The Problem Solver called Bank of America spokeswoman Betty Riess, who agreed to look into the situation.

On Tuesday, a Bank of America representative called Greenwood and told him again the charge was related to the $1,450 credit, but the company would erase the $39.23 interest charge anyway, Greenwood said.

"They're going to give me my money back," he said.

Riess gave the Problem Solver a different explanation of the interest charge. She said the issue was not with the $1,450 in credits Greenwood received, but the fact that he had carried a balance from July to August.

Bank of America decided to refund the $39.23 "as a courtesy," she said.

Greenwood said he did have a $600 balance, but that money was supposed to be charged zero percent interest as part of a promotion.

Besides, he said, the $600 was included in the $5,734.13 he paid.

Greenwood said he's glad to have the interest money back, but remains fuzzy about what actually happened.

"They never gave me a real good explanation," he said. "I'm not sure that they understand it."

facebook.com/chitribproblem

Twitter @wyp_tribune