Hello,
I'm Nerys I work for 123-Reg.
When a domain name expires, rather than the domain being released straight back onto the open market, domains will be held for a certain period. This period will vary depending on the extension and the registry which the domain name is with. During this period the registrant will have the option to retrieve the domain name, although a fee may be payable.
As there are variations between domain names, for both the cost and length of grace period I cannot say what the status of your domain name is without some further details.
If you wish I would be happy to look into your domain name for you. Please provide the domain name or support ticket ID and I will happily investigate and be in touch with further advice.
Regards,
Nerys.