My parents have a 40ft Swift Chamonix, 2013 model. In that space of time we've had three leaks, one of which has been ongoing for two years now in the apex above the front door.
It's been badly patched up on one occasion only to find out the actual cause is a series of hairline cracks in the fibreglass roof panel.
Swift have agreed to come in person to fix this now for a substantial cost to us, obviously 4 years is out of warranty.
My real concern however is they have requested payment in full before they even arrive! My parents, both in thier 70's have paid this and told it could well be two weeks before work commences but I'm not holding my breath.
Looking at the aftersales reviews on Swift natrally I'm concerned. I was told by someone highly experienced in holiday homes most Swift products will leak, followed by incredibly bad aftercare.
Shame they’ve paid already. If the problem was originally treated within the warranty period and is still not fixed, I think it should still be done under warranty as Swift we’re aware of it within that time. It might be worth your parents seeing a solicitor for a free half hour.