Firstly... glad to see that you are safe!
I think that many dive operators would schedule the swim test at the beginning of the course. Where students encounter problems meeting those minimum standards, they typically need more than a week to remedy the problem. In many cases, the (IMHO) prudent course of action would be to take pressure off the student and re-schedule them onto a later class - rather than expect them to work miracles within a week.
Whilst the course standards may allow the swim test to be completed at any time prior to certification, the dive operator may have valid reasons for wishing to ensure student water safety
before in-water training commences.
Not least of these might be the fact that a subsequent failure to meet the swim standards could result in the need for further payment to cover refresher/supplemental lessons, should a course delay occur. It's better to delay start of the course, rather than delay completion.
Most dive operations clearly state the certification requirements for their courses. I am surprised that the students concerned didn't make a visit to their local pool,
in advance of the course, to confirm their swimming performance. Perhaps they thought that the certification was automatic, or attendance based, rather than dependant upon them attaining a minimum standard of capability for their subsequent post-course safety?
In the case of this thread, it seems that the OP is expecting the dive operator to provide remedial swimming tuition for the student. Unless that was advertised as part of the course content, it would be unreasonable to expect such service from a dive (not swim) instructor.