You've not mentioned which phone service provider you're with.
With Vodafone, large areas of Knutsford only have coverage described as 'outdoors only' or, at best, 'outdoors, variable indoors':
https://www.vodafone.co.uk/explore/network/uk-coverage-map/index.htm
EE shows 'Good outdoor coverage, weak or no indoor coverage' for the area as a whole:
http://ee.co.uk/ee-and-me/why-ee/uks-no1-network/mobile-coverage
Three has 'No coverage' for most of Knutsford, with 'Outdoor' available in just a few local areas:
http://www.three.co.uk/Discover/Network/Coverage
O2 shows 'Good outdoors' on the south-east side of the town but 'No Service' everywhere else:
http://www.o2.co.uk/coveragechecker
So I doubt that you've got any usable 4G coverage where you are, which would explain why your phone doesn't offer it to you!
It could be worse though. Here in Suffolk, 3G is considered a luxury in many parts of the county, with 2G still being the best that some areas can get. (There are also still quite a few areas with absolutely no mobile phone signal at all!)