oil in coolant

[sharpie75]

I bought a 2020 corsa f 1.2 sri just over 6 months ago with 11,000 miles on it .. I have done just over 8,000 miles since buying it. The other day whilst doing some checks I noticed that the coolant bottle had a film of oil in it and that there was a thin layer of oil sitting on on top of the coolant . The car has not been overheating , there has been no white smoke or anything . I tried to do a bit of research as I was fearing cylinder head gasket , some research pointed to it could be a fault with the oil cooler , I have I have got my garage to replace the oil cooler , flush and replenish the coolant and do an oil and filter change ( as its due anyway for service ) ..And see what happens ... but my point really is , why would the car have developed this kind of issue at such low milage ?? Maybe Im just a bit too old school and expect things to last a little longer than that ... Im really praying it is not the head gasket as that will be ££££££ any feedback / comments welcome ... oh and car is out of 3 month warranty it had.