Law firm Maurice Blackburn Lawyers has launched a class action in the Federal Court in Sydney against Thorn Australia Pty Ltd, which trades as Radio Rentals.Law firm Maurice Blackburn Lawyers has launched a class action in the Federal Court in Sydney against Thorn Australia Pty Ltd, which trades as Radio Rentals. It's part of the Thorn Group, listed on the ASX with a market capitalisation of just over A$200 million.The class action claims that Radio Rentals customers paid excessive amounts through what the company called "Rent Try $1 Buy" leases. They say that, contrary to Radio Rentals' advertising, customers were not entitled to buy the rented goods for $1. The law firm is also taking action over the financing of purchases, where customers - often on Centrelink benefits -  pay up to five time the value of an item over the term of the contract.Ben Slade, principal at Maurice Blackburn, said Thorn "imposes on its disadvantaged customers onerous and unfair terms that avoid credit laws that prohibit overcharging."The firm's client Casey Simpson is the lead plaintiff, alleging that Radio Rentals engaged in misleading, deceptive conduct or unconscionable conduct, and that Radio Rentals contracts contained unfair contract terms.Maurice Blackburn asserted in a media release yesterday that the claim could be worth up to A$50 million, with up to 200,000 consumers potentially affected across the country.Karen Cox from the Financial Rights Legal Centre said the practice needed to be called out and stopped.In response, Thorn Group Limited released a brief statement in which it acknowledged "media commentary" over "a potential class action to be commenced against the Company in connection with its past lending practices." The company observed that, as it not been served with any statement of claim "to date", it cannot comment further, although it said: "should any proceedings be commenced, they will be defended vigorously."With Thorn Group is about to close off its books for a financial year ending 31 March 2017, the class action announcement comes at an awkward time for the company's consumer leasing division.Thorn was forced only last week to issue a downward profit guidance note over the ongoing Australian Securities and Investments Commission investigation into Radio Rentals' responsible lending obligations. That announcement flagged the group's intention to boost by $4 million a provision in its accounts for "compensation that may be payable to customers who did not meet minimum income thresholds for their contracts".Thorn disclosed that ASIC is likely to push for a civil penalty, along with "further compensation and remediation", pushing the group's net profit after tax down to range of $24 million to $26 million.