Hi Karen, turnover of staff in the cleaning industry is relatively high compared to many others but for many to quit after such a short period is unusual.
Notoriously cleaners change jobs for an increase of 10p an hour. Maybe you're not paying a high enough wage. It's sickening to recruit and train staff only for another contractor to benefit from your time invested in that person, or in your case people.
If it's not the wage rate could it be the working conditions on the contracts that you have? (I'm assuming that this is happening over several sites - not just one.) This could be the shift times, the duration of shift, the working environment etc.
If there is no common link maybe they just don't like you or your management style - but I find that hard to believe, all us users of this forum are such lovely people.
If you want to give more information to enable me to narrow down the possibilities I may be of more assitance - I'd need to know shift start and finish times, type of work involved (inc factory/office/school etc), the wage rate you are paying and the Post Code of the contracts you are having problems on (this will help to confirm whether the wage rate is sufficient).
I appreciate that this is sensitive information so you may well not want to publish it to all and sundry - in which case send the info via a personal message.
If your work is domestic cleaning maybe someone else can help you as everything I know about that sector can be written on the back of a postage stamp!
Hope to hear from you soon, but any reply will not be forthcoming until tomorrow as I'm out on the lash in Notts tonight.
Musicman