Tinker Tailor Soldier Spy

I know the film's critically acclaimed and I can see why - especially in the UK. But if I am being honest here I have to say I don't like it at all. Disclaimer: I didn't know ANYTHING about the film / book before seeing the film, other than it's about uncovering a spy.
What I don't like about the film in particular:

• The characters are very confusing - having read absolutely nothing about the book / film before seeing it, I don't know the name of any character, and I think they're not clearly given out. There are confusing names like 'Control' - call me stupid but I didn't realise it's the head of the secret intelligence service until perhaps the end of the film! I was thinking it's similar to what 'circus' is in the film - there's a great deal of jargon they use and a guy whose name is 'Control' doesn't make it easier for anyone. And honestly I don't remember any of those agents' names... and I think there are too little details given about each one of them, which is weird because the film is essentially about finding out the 'mole' among the few of them. The lack of detail (depth) about these characters renders the film very superficial and a plain narrative, in my opinion - the audience is not given any clue as to who the 'mole' is and there's no way they could have guessed it. You're just told in the end who it is - and that's it. Where's the suspense? 
• The relationships between different characters are also very confusing. There's this guy (who I still don't know the identity of) who seems to be above the whole secret intelligence service, and then towards the end he's kind of told off or threatened by Smiley. And then there are all these deaths surrounding the wife of the Moscow agent - one's her husband? Then who's the other one? I'm just completely clueless. Then she's taken away, and when Prideaux is asked if he knows her and he gives a negative answer, she's shot dead on the spot. Why? I don't know if I missed something but all this is just confusing to the max to me! 

I have to say, I don't think I'm the only person who finds the film confusing - I saw lots of puzzled faces after the film and people were asking one another about things in the film... oh well. I can't fault the acting though, but if the whole film takes so much effort to understand in the first place I wonder if we can still call it enjoyable.