Using the clubs on line booking

We recently booked a few sites using the online booking forms/system

On each site I filled in the required information - No. of Adults; zero children; No. of Age Conessions

Filled in my credit card details: came to the submit box

The system accepted my booking and sent a confirmation > Three (3) for each site

I then had to contact the booking office by telephone to ensure that we had not booke the same site three times and had been caharged three times

No only one payment had been made

Is this a common fault or was it a once only glitch