Kenwood DF310

Basic design fault with Kenwood DF310 lid, refuses to stay closed when fryer is hot. Bought one and thought it was just a problem with that one, swapped for another and have the same problem but worse this time as lid won't remain open enough when you do want it open to be able to load the basket. The customer service person I spoke to at Kenwood said 'the problem might be because the lid gets hot'- er, that's what's supposed to happen isn't it? Customer serices at Kenwood were worse than useless and I shall be taking this back to Tesco (who have been good) who I bought it from and changing for another make