I said that you didn't need to hurry to pay me back,
but now I need it back by March 29.
Please make sure to transfer the money to my account by March 29.

Is my sentence natural to say?
Please give me your suggestions?

I'm not a native speaker so I won't comment on the flow.

From the grammatical standpoint, there's a redundancy - March 29.

Another thing I noticed is the second need. I would prefer to say 'I'm going to need it back " though I'm not sure that's right to say.
Thanks, New2.