Need urgent help or I'm going to jail

Hi all.

So long story short, my phone broke early Jan and I took my sister's microwave in the garage and loaned it for R400. I was supposed to go fetch it before the end of February but my sister found out and is angry as I hadn't told her, I need R540 to get the item back or I'm going to jail.

Proof of the loan is with me and I can DM it. I'm in South Africa.