If one spring has 5 coils and the other 3 then there is a problem if 5 coils is the Nissan spec then only a spring with 5 coils should be fitted,sounds to me that they have found a spring in the garage that is roughly the same size and fitted that personnaly I would not only change the spring but also change garages..

Your garage should have fitted an original Nissan spring or an aftermarket one that is exactly the same.

If the original had 5 coils and the new one only 3, then the new spring must have a different spring rate in order to support the vehicle weight. This will change the charcteristics of the suspension on that side. So now you have two sides on the same axle with different characteristics instead of being the same. Also you don't know if the new spring rate is suitable for use with the original shock settings (or vice versa if you prefer).

Expanding somewhat:

Actually it is possible to design a spring with 3 coils to have the same rate as one with 5 coils, but in order to do so the wire diameter must be smaller. This brings other problems - for the same amount of suspension travel each coil must compress further, stresing the smaller diameter wire even more. Smaller diameter wire will be "weaker" - it'll have a lower fracture threshold. Smaller diameter wire ends may not sit in the seats as well. And you can bet that cheaper springs will be made with cheaper wire (as well as having less wire in the spring reducing cost still further).

As the X Trail is ostensibly an "off road" vehicle, problems could be further compounded if you ever actually give the suspension any serious work to do.

I would always caution anyone who is changing the characteristics of their suspension tobuy from a reputable source with a brand name (koni, Bilstein etc) .Spring and damper rates needto be matched to provide proper ride and handling quality. Poorly matched springs and dampers can also have a devastating impact on stopping distance as the suspension may struggle to keep the tyre in proper contact with the road under emergency braking conditions.

Get a proper spring fitted and, as suggested, find yourself a new garage.

I'm self employed these days and have a Cit Dispatch van. Front right spring broke when vehicle only 4 years old and 40k. I changed the broken spring myself (using an OE replacement). The vehicle is now 10 years old and 80k up. No problems with th other side.

I took my own advice (or rather, the advice of fellow Professional Automotive Research and Development Engineers from a Chassis Engineering background).

Even back in my rallying days, we had a couple of spring breakages and only replaced the broken one.