Upvote:5
They got you on V 4.2 (a) + (b). These two taken together in the overall context of the refusal indicate that you are an applicant who intends to go underground and eventually build up a case for settlement.
They reached that conclusion by seeing that your bank accounts suggested a highly disproportionate amount reserved for your trip and genuine visitors plan to spend a more reasonable level of their reserves.
They also noted that you have contacts in the UK who might be willing to harbour you unlawfully while you looked for work or built up a case for settlement.
Your showing them return air tickets will not change the conclusions they have reached. Air tickets do not establish intent to use them.
If rejected again, will I be banned from visiting the UK?
There is a clause in Paragraph 320 where they can ban a person for frivolous applications, you should try to steer clear of it by substantially improving the quality of successive applications. Otherwise it's fine to try again if you think you can improve the result.