The US government plans to speed up the pace of processing up to US$3bn in “cash for clunkers” reimbursements to auto dealers and hopes to complete the job by the end of the month, officials have said.

One major dealer group reported this week it was owed $500,000. Dealers, through their main trade group, have complained the transportation department’s online processing system was cumbersome to use and too slow to respond to some 700,000 rebate applications between the first week of July and the third week of August when funding was nearly exhausted.

Most of the 3,000 people involved in processing are contractors, and government officials have acknowledged computer system breakdowns and other problems handling the avalanche of applications from 16,000 dealers, Reuters reported.

Transportation Department officials told the news agency the government had so far processed about $500m in rebates from 120,000 sales while the goal in coming weeks was to add more workers to process about $100m in rebates per day.

Citigroup is in fact handling the paperwork.

Bailey Wood, legislative affairs director for the National Automobile Dealers Association (NADA), told Reuters the pace must be faster.

“We’re far from solving the ultimate problem,” Wood said. “Dealers are still floating the government billions of dollars.”

Transportation secretary Ray LaHood this week said any new clumkers programme would be up to Congress.

Meanwhile, car buyers guide said it intended to advocate (with the NHTSA) for consumers who might have been unreasonably rejected after making their purchase and having their clunker disabled.

“For example, we’ve heard of cases when names appeared differently on the various papers they had to submit, and people who had a couple days lapse in insurance coverage because of a billing issue and families who traded in their ineligible clunkers before the mileage change was announced,” Edmunds said.