advice please coolant leaking

hi i have a discovery 2 td5 landmark 2004 vintage and over the last two years it has had
head gasket 12/2012. new rad/water pump/thermostat/viscous fan and cylinder head gasket 12/2013 (had kenlowe fan that was selective about when it wanted to work)
recently i had to lay it up for a month whilst the bottom ball joints were replaced but since i have started using it again it is blowing coolant out of the header tank return on the radiater, the hose clip is as tight as i can get it so i fear the worst and that the head gasket has gone again, it was done at a specialist landrover garage last dec so is still under warranty but to be honest i have lost all faith in it thanks for reading appreciate some advice

Assuming the first HG was for an overheat was the head checked / skimmed to make sure it was flat as a warped head could cause premature gasket failure

the head was skimmed first time around but because of the damage a new head was fitted second time around

Was that a new 'new' replacement head or a second hand replacement? If second hand it may possibly have been warped already if previously overheated. If new I assume it was correctly torqued down on fit? If it was then you may have a cooling blockage somewhere which is causing continued overheat issues

hi yes it was new new i fear the worst but as a precaution i am going to fit a new header tank cap as read on here it can cause pressurization if faulty i can honestly say that i have fallen out of love with landrover cant wait to fix it and change it for something japanese thanks for your comments