booking for client problems

I Have 2 properties with booking .com.

Ian  having problems with the system overbooking and never blocking the date when first  booked.

when I have an up and coming booking I find it isn't blocked out on the diary then I have to go in and close the date myself.

when overbooked it can be 3 or 4 times overbooked ,I cannot be to blame as your system isn't working.

Most agents when calling up do not know how to help even after ringing multiple times to sort out they will speak to technical never hear anything.

I also have date blocked out with air bnb bookings but don't have any.

and the system keeps shutting down the whole booking system as if its booked or not available.

then you get the usual message saying you'll get charged.

also taking 1 night bookings which we have never done but is set up as 2 night minimum,

WE GOT OVERPAID APPARENTLY BUT NO PROOF PROVIDED

PLEASE CAN SOMEONE CONTACT ME ON 07860703393 FROM TECHNICAL TO SORT THESE PROBLEMS

THIS IS VERY STRESSFUL AND DONT KNOW WHAT TO DO AS THIS IS DEFINATELY A TECHNICAL ISSUE AT YOUR END