Having thought about this problem a little more I would suggest the following course of action.
You said the pump ran for five minutes before blowing the fuse. I would not expect the pump to run for more than a couple of minutes after which the suspension should be to height and the pump switched off. Further you say the back rises but the front doesn't, this may be because there is a blockage to the front suspension or the EV (in the pump is closed).
My feeling is that the pump is running for so long because there is a problem exterior to it, maybe t the rear height corrector is not working and the pump is continuing to pump a fully extended cylinder, if the front system has a problem also this may well overload the pump.
First thing to do having replaced the 50Amp Fuse with a 60Amp is to select the suspension to the low position. In this position the pump should only run for a few seconds if it runs at all and the back of the car should not rise, if it does then this would suggest that there is a problem with either the height sensor or the Electrovalve which is within the pump assembly. Would be worth checking that the Height sensors both front and rear are NOT seized.
At this point without a Lexia the only way of proving whether the problem is the ElectroValve in the pump or the height sensor is by substitution. There may be some value in switching the front and rear height sensors however as you have no certainty that anything is good it may be worth investing in a new height sensor.
If this works i.e back doesn't move pump doesn't run and fuse is still intact then the next thing to do is to use the boot switch to raise the rear suspension (advantage of the estate!
Ah! you don't have the user manual, in the boot LH side looking in you will see a Rocker switch with this you can raise and lower the back of the car for optimal loading height. This will work with the engine of so now the suspension is on it's low setting but using this switch you should be able to raise the rear to Max Suspension height at which point the pump will switch off should take about 45 seconds.
Right suggest you do this and let us know the result don't really want to write lots if you aint interested.
Cachaciero