Cadiz flats rent out for a premium during the summer....no joke, flat rental contracts usually go only until June and do not start up again until October so that the owners can jack up the prices three or four times the normal rate for July-September. Nothing wierd about it, Cadiz is on the ocean and it's a prime destination for Spaniards on holiday! Unless your language school has accommodation possibilities, you may be forced to stay elsewhere...San Fernando is the bedroom community just across the way and rents tend to be much cheaper..have you tried infohostal or Loquo? You are much more likely to find accommodation offers on Spanish pages for these cities. The publication Cambalache may be useful as well, but be prepared for flats that rent out at 1000+, just for a "quincena"...