Records in 5 min segments

Hi, I've just bought an X4S with hardwire kit and installed it quite easily in my car. Although I have the overwrite interval set to 'off', it constantly records in 5 minute segments so the SD card is full of 5 minute segments from front and rear cameras. I have contacted customer service but don't really understand what they said. I think they said that it's a firmware problem and, initially, said that it would be fixed with the next upgrade. I asked when that would be, but the answer was very unclear and, I think, said that the engineers have said that it is a firmware problem which can't be fixed. Am I right in thinking that both cameras should be able to record continuously, so that a long journey down the motorway for 2 hours would be captured in one long segment? If so, would I be able to downgrade to a previous firmware version? Any help would be greatly appreciated.