offer rejected

I made an offer on a property this week.

Agent took my offer then at 6pm called to say he was writing up another parties offer and asked if I wanted to change anything on my offer.

I said my offer would remain in it's current form.

2 hours later I receive a call and he says they are negotiating with the other party. He then said they haven't written rejected on my offer.

My question is are they required to write rejected on my offer or can it be returned to me blank without written rejection?

I ask this as I am now wondering if he even presented the offer in the first place.

Thanks

JS