The claim follows revelations that more than 1,300 domestic abuse cases are waiting to go to trial at Glasgow Sheriff Court.
Court bosses have added an extra court each Friday and an additional daily trial court is planned next month to deal with the pile-up. But advocacy chiefs say there were also plans for extra court resources in November, which have now been "taken off the table".
Now they are calling for a long-term solution. It was thought the change in plans was down to a roof fault at Glasgow High Court, which led to one of the six courtrooms being close for repairs.
It meant some business had to be temporarily moved to the sheriff court. However, the Scottish Courts Service said it had no impact on summary business.
It said it had looked into setting up additional domestic abuse courts this November, but a decision was made that the extra resources would only be provided in October.
When the flagship court was set up in 2004, the aim was to fast-track domestic abuse cases within eight weeks.
Mhairi McGowan, head of advocacy group Assist, said the lack of action was resulting in abuse victims waiting more than six months - more than three times as long - for their cases to be heard.
She said: "We welcome the plans to provide extra court resources for domestic abuse cases this month and in October. But there were plans for an extra court in November, too, and those plans have now been taken off the table.
"This means people could be waiting up to 29 weeks - when the aim of the Domestic Abuse Court was to fast-track cases in eight weeks. We need to do as much as we can to get through the backlog of cases and make sure cases are dealt with promptly.
"The issue is, if we are only putting on extra trials in October each year, we are just putting a sticking plaster over the problem."