Help! Late payment

So we were moving house at the end of last month, I packed away our wedding paperwork thinking I was on top of everything.
I just started unpacking and sorting some wedding bits when I noticed our registry office payment was due 2 weeks ago (Bristol) and we missed it. I had it down as due next month. Tried to call to pay but they are closed until Monday. I've had no cancellation email or call from them, although if they posted anything it may have gone to our old address and I would have missed it. Looking for reassurance- surely they would contact us if they've cancelled the booking??