what to do if ur task is rejected unfairly?

I agree that if the task-setter rejected it (for whatever reason) there is little you can do. MyLot do not guarantee the validity of tasks set here by others. You accept the task at your own risk, effectively.

Unfortunately, subha12, the standard of English required in the tasks is likely to be higher than you are capable of at the moment, judging by your posts here. You have to realise that what you consider 'unfair' is based on your perception of your own ability. That may be good enough (and, indeed, usually is) for your discussions and responses on the discussion board but you will have to accept that it is not acceptable for certain of the tasks. We are, I know, not supposed to criticise other members for their spelling or grammar and normally I would not do so but, in this case, I think that it is constructive to point out that you may consider something 'unfair' because you have misunderstood the standards required.

First of all I think I should thank you for your comment where I came to know from you that I write very badly. Then I want to say English is not our mother tongue and still I believe many people from our country write much better English than people who have English as First language. Anyway, I must say for the first time I have come across some response where it is distinctly mentioned we are all wrong and very bad writers.

If your text was too close to someone else's then, regardless of whether you had actually copied it or whether, by chance, your words and phrases matched someone else's, then it would be classed as 'plagiarism'. I cannot comment, of course, on whether or not it actually was. I can only say that there are plagiarism checkers out there that are very good and will score a piece of text very accurately.