re: "The client paid me for the trial and I felt to refund the money as the project didn't execution did not happen."
You worked on behalf of the client.
The client paid you in good faith.
The client was acting ethically and responsibly.
You were not supposed to refund the client's money.
re: "The client was happy with my work and professionalism and gave me a good review, but since I refunded the amount the review is not visible on my profile."
You are correct. That is how this works.
If you issue a complete refund for a contract, then the contract will not appear on your profile page. The review won't count. Freelancers normally avoid zero-pay contracts because they can have a negative impact on JSS.
re: "Can I please get some help on this."
Yes. You have received help from me in the form of information about your situation.
You can not receive help from Upwork.
This is over.
