What do I do to get approval to my uk visit visa?
Okay so you were refused under V3.6 (a) and V4.2 of the Appendix V of Immigration Rules, although the 4.2 is not important here, so let us bring up V3.6 for reference as this, is the onus of your refusal:
V 3.6 An application will be refused where:
(a) false representations have been made or false documents or information have been submitted (whether or not material to the application, and whether or not to the applicant’s knowledge);
This is a very serious refusal as this means that they have got you on providing false information which is about the worst thing you a visa applicant can do. The letter also goes to explain that any future application may refused under V3.7 of the same appendix which would attract automatic 10 year ban.
So your next application will not only fight an uphill struggle as the refusal under 3.6 will be read by the ECO who will be handling it and because of it will receive extra scrutiny, but also if it's not successful you may attract the ban. Because of that you should find a practising solicitor who specialises in such cases, this is something that will be expensive, likely well into thousands of pounds, if you can even find a solicitor who would be willing to take your case.
What you really do not want to do is file another application without such representation, and do not try to hire some "immigration specialists" or other "travel agents" who do not have a registered practice in the UK as they will likely take your money away and do nothing good for your case.
Engage an immigration solicitor, preferably from the UK, before you make any new application.
You are on a knife edge and only an expert in the field of U.K. immigration can prevent a 10 year ban now.
It won't be cheap.
Your only alternative is to forget visiting the UK for the foreseeable future.