More on KentOnline
The Post Office at Tonbridge Castle will not now reopen until Monday, January 9, it has been announced.
That is three days later than originally promised when it shut due to staff shortages two weeks before Christmas.
A spokesman said: "We apologise for any inconvenience caused by this short-term closure being longer than expected.
"In the interim, there are alternative branches at York Parade, Higham Wood and Hildenborough.”
The branch has been plagued with problems ever since it opened at its current site in August.
Even when the branch has been open, it has been unable sometimes to offer a full service because of poor internet connectivity.
It had previously been based in WHSmiths in the High Street but the store closed on July 30.
Green Party councillors Mark Hood and Paul Stepto have been campaigning for it to be moved to the town's library.
Following the latest announcement, Cllr Hood has written to Nick Reed, who is in charge of the service for the Post Office saying: "Since the closure of our main Post Office in July we have had at least 68 days without any town centre service.
"Cllr Stepto and I, as Kent County Councillors for Tonbridge, are not satisfied that enough is being done to resolve a completely unsatisfactory situation which has failed local businesses and residents which is affecting your long-term business as people will look elsewhere if you cannot deliver.
"Please look into the substandard provision of services in Tonbridge as we have very little confidence that this situation will be resolved given our experience so far."