Buyer's agent listed property for rent before closing

[Sarah Johnson]

A day before we close, we found out that the buyer wanted an extension. We have been in closing for 6 weeks already and they are asking for another 2 weeks. We found out that 8 days ago the buyer's agent had listed our house for rent on Craigslist with availability date Aug 1st. We also know that the buyer's agent had been accessing our property more than usual after we accepted their offer. They had taken new photographs to use for the rental listing. Not sure if they are showing the property as well. I'm pretty sure they are accepting applications while the vacant property is still mine. They never asked us for permission to do any of this but instead the buyer's agent had been really hard to contact and only prefers to communicate by email with our agent. We bought this property with cash, it's all paid for so we have our downpayment money for the next house tied up in this one. We are closing on our new house on the 27th and the buyer is requesting closing on the 28th. I'm stressing out over this. Is the buyer's agent allowed to list our house for rent while we still own it? Any opinions will be very much appreciated!