An angry iPhone buyer is suing Apple for $1 million (£490,000) after the company slashed the price of the device by $200 only 68 days after its US launch.

Dongmei Li, of New York, who waited "for hours" to buy a 4GB version of the iPhone in July three days after its debut, is accusing Apple of "price discrimination, underselling, discrimination in rebates, deceptive actions and other wrongdoings," according to a filing by her attorney, C Jean Wang, of Wang Law Offices.

Apple cut the price of the 8GB model of the iPhone to $399 from $599 last month, triggering an outcry from consumers who had stumped up the higher price for the much-hyped gadget.

At the same time it phased out the lower-specification 4GB model.

Under an existing return policy, Apple refunded the $200 difference for those who bought the phone within 14 days of the discount.

Later, in a bid to make peace with irked early iPhone adopters, it offered a $100 credit to purchasers at Apple stores.

However, according to Ms Li’s lawsuit, filed in the US District Court, Eastern District of New York, the discount “injured” early purchasers such as herself because they cannot resell their iPhones “for the same profit as later purchasers”.

The high-profile iPhone has proven a magnet for lawsuits – some with more apparent merit than others – since Day 1.

Only hours after Steve Jobs unveiled the gadget in January, Apple was sued by Cisco, which claimed that it owned the “iphone” brand. The two technology companies settled out of court.

In August Herbert Kliegerman filed a class-action lawsuit in New York State Supreme Court, claiming that the company had misled consumers.

He filed the action after being hit with a $2,000 bill for roaming charges when he used his iPhone outside the US, which he claimed he was told would not be imposed.

Two other lawsuits making their way through US courts contend that users cannot change the iPhone’s battery.

Ms Li's filing against the iPhone reasons that "market conditions did not require Apple to change its price”.

It adds: "iPhone was selling very well because Apple's stocks were increasing since August 16, 2007, and rose as high as $144.16 on September 4, 2007, the day before Apple announced that it was cutting the price of iPhone."

Announcing the $100 credit note last month, Mr Jobs, the chief executive of Apple, acknowledged that his company had failed to look after iPhone customers.

He said on the Apple website: “Even though we are making the right decision to lower the price of iPhone, and even though the technology road is bumpy, we need to do a better job taking care of our early iPhone customers as we aggressively go after new ones with a lower price.”

Times Recommends

• Lies and cover-up at MG Rover exposed by report
• High oil prices push manufacturing costs up
• Primark founder steps down as chief executive