Refunfs

If you didn't do the job, you don't deserve the money.

I suggest you immediately return the deposit.

If you don't, he'll probably sue you, or worse; continue to tell the world that you stole his money.

Actually, you didn't do the work, the money isn't yours.

You didn't earn it, you simply used it in advance of doing the work.

If you don't fix this, it'll destroy your business. Be smart, fix it!!!!

 

Why do you want to know how long you have to pay the money back - if you didn't do/aren't doing the job, return the money now.