Nostalgia has its place, but when it comes to staying away from home (and at the prices charged) you generally don't want to stay in accommodation where the fittings and fixtures look older than the house in which you grew up.
So we checked out of there and found an alternative, and I sent a polite email to their head office suggesting they invest in renovating the site or change the motto of the hotel to "where the 1960s and flat-screen TVs collide".
Your business may have issues with suppliers from time to time and in such cases it is even more important not to accept substandard service because their failures will transfer to the experience and value received by your customers. So there is a "double negative" here and it is vitally important that you take control of it.
If you have service-level agreements and/or documented quality standards you should enforce these and make sure you do everything you can to avoid a repeat.
It is said that we Kiwis don't complain enough and there is truth to that. If you don't like to complain or don't like the word it might be time to change your approach, because you deserve the best when it comes to parting with your hard-earned money.