As I understand it, ICANN rules state clearly that domains which expire and are not renewed by the holders are supposed to drop and be available for anyone - repeat anyone - to register.
The link below is the Expired Domains Deletion Policy:
[icann.org...]
See where it possibly says expired domain names are "supposed" to drop. A lot
of them actually do, but they're quickly snapped up as you observed.
OTOH, if you have "tangible" proof that a registrar is violating any term of their
registrar agreement, feel free to complain via the link below:
[icann.org...]
David
"In the absence of extenuating circumstances (as defined in Section 3.7.5.1 above), a domain name must be deleted within 45 days of either the registrar or the registrant terminating a registration agreement."
"Extenuating circumstances are defined as: UDRP action, valid court order, failure of a Registrar's renewal process (which does not include failure of a registrant to respond), the domain name is used by a nameserver that provides DNS service to third-parties (additional time may be required to migrate the records managed by the nameserver), the registrant is subject to bankruptcy proceedings, payment dispute (where a registrant claims to have paid for a renewal, or a discrepancy in the amount paid), billing dispute (where a registrant disputes the amount on a bill), domain name subject to litigation in a court of competent jurisdiction, or other circumstance as approved specifically by ICANN"
Seems pretty clear to me that if the registrant doesn't renew the domain has to be deleted within 45 days. Unless I'm missing something?