Service provided was not as ordered

[#1]

Some months ago when we ordered a Business ADSL service for one of holiday homes through PlusNet it went reasonably smoothly. The router was delivered in time to the correct address. OpenReach did its bit and livened the service when scheduled. We get a reasonable speed of Broadband, circa 16 mbps.  We ordered a single static IP address, but were not given details of the address. However using a  remote Whoami I was able to discover the IP address of the router. The service has been reliable, but last night, just before the guests arrived I noticed a red light on the router. I had to resolve this quickly so I rebooted the router and things started working again.
However when I tried to remotely access equipment at the cottage I discovered I couldn't access anything. A brief investigation discovered PlusNet had supplied only a Dynamic IP address set up for the holiday home. I think I'll be able to resolve this myself when we don't have guests in the property, so this is not a request for support. Nor is this a request for an apology.
This posting is however an observation that PlusNet were careless in their service provision. It is another sign of the slippage of service quality. Business clients pay extra for the service, we expect delivery without problems. I've already swapped to Zen Internet as my main provider for new business, but I'm afraid PlusNet has been kicked further down the heap.

[#2]

Hi there,
I'm sorry to hear about these issues, if you could provide the username for the account in question then we would be happy to look into this and why the Static IP was not applied. Thank you.

[#3]

Thanks for the offer of investigation, but I'd prefer the service is left alone as it is working [though not as specified] and I can't afford outages while guests are staying. I'll arrange for a fix at a convenient time.
I'd have greater confidence if I thought PlusNet would perform genuine Root Cause Analysis leading to a change in procedures.  However I think you'll end up just saying someone made a mistake and you are sorry.
As my old Finance Director of a major City of London financial house used to say: "In this business you either succeed or you fail."