Bad service not paying on time

My invoice was due for payment on the 30th December however it is still outstanding to date. After numerous emails to the company I have only received an automatic reply that they will be reopening on the 17th Jan 2022. The payment delay is obviously in their interest and on the customer's interest I was under the impression that the above company is reputable was not expecting to have such shoddy service after submitting my valuables to be sold by them.

Ps I wonder how many others customers money they are withholding