What are my rights with a holiday letting agent cancelling my booking after confirming it?

Sorrento

I  made a booking at the beginning of June  for a holiday cottage with the Plum Guide. The booking was for next June 2022
The booking deposit was accepted and I received a confirmation email from Plum guide
Then suddenly with no explanation I noticed the deposit money had been returned to my account
To summarise - after several unsuccessful attempts to speak to Plum Guide - eventually Travelzoo connected me to a plum guide agent who said they and the owner are arguing about the cost as it is more than Plum Guide had advertised - no response since. 
I suspect Plum Guide made a cost mistake on their website and just hope I will go away. I have messaged the owner and he says this is the case. Plum Guide said the owner wasn't responding to their efforts to sort this out but I doubt that because he has been quickly responsive to my enquiries
Can anyone help? Do I have the right to ask Plum Guide to stand by their original confirmation and meet the difference in price themselves? It was their mistake after all
Thanks

[Deleted User]

Sorrento said:

I  made a booking at the beginning of June  for a holiday cottage with the Plum Guide. The booking was for next June 2022
The booking deposit was accepted and I received a confirmation email from Plum guide
Then suddenly with no explanation I noticed the deposit money had been returned to my account
To summarise - after several unsuccessful attempts to speak to Plum Guide - eventually Travelzoo connected me to a plum guide agent who said they and the owner are arguing about the cost as it is more than Plum Guide had advertised - no response since. 
I suspect Plum Guide made a cost mistake on their website and just hope I will go away. I have messaged the owner and he says this is the case. Plum Guide said the owner wasn't responding to their efforts to sort this out but I doubt that because he has been quickly responsive to my enquiries
Can anyone help? Do I have the right to ask Plum Guide to stand by their original confirmation and meet the difference in price themselves? It was their mistake after all
Thanks

 Nope, no rights. It was an error and they rectified it.