Not sure what I should do...

[bright sparks]

I think the answer to this is quite simple...yes, call them. It is not fair that they pay you late regardless of the time of year but even more so because it is xmas. If it is just a genuine oversight which happens, then they will be very apologetic and get payment to you quickly. If you get a voice mail, under no circumstances should you down play the situation. If you try to be nice nicey to them then they to will have a lax attitude to the situation. Simply say that payment has not been received and that it is a matter of urgency that requires their immediate attention due to both being able to make your payments on time and also due to the expense of Xmas. Also make it clear that there is a daily late fee and in addition to this any charges incurred as a result of their non payment resulting in your bills not going through will be expected from them.

Ask them to call asap to acknowledge the phone message and once this has been sorted out ask them to be sure to bring you 3 months of posted cheques for future payments so that daycare is always paid for in advance and assurance that you will be able to stick to a budget. Put your foot down!!