Wrong number - inherited problems

As part of the facilities in the holiday home I've added a phone system. It uses the same VOIP (Voice over Internet Protocol) technology as I'd recommend for a small business. We use a hosted service which means the hard technical work is done by an external company. All we have to do is plug in a phone to the cottage Internet and change a few technical parameters and it works.

We've configured the service so that it acts as an extension phone. All the guest has to do to contact us is to pick-up the handset dial 10 and they will be connected to me free of charge. To prevent costs spiralling we restrict outgoing calls that would attract a fee. If the guests need to use the phone for outgoing calls we can switch on the facility in a couple of minutes via a web browser. At the end of the stay we can present a an itemised call bill to the guest. Usually however guests use their own mobile phone for their calls. We can also prevent calls to expensive numbers. It costs us about £3/month to provide the service, calls are additional but cheaper than BT tariffs..

The phone comes with a local DDI number so the family and friends of the guest can call the number on the cottage phone. There's no charge for these incoming calls and the phone has voice mail capabilities. When we were choosing the number we were able to get one that is easy to memorise. The number ends as 888111, which is pretty easy to remember. However this is where the problems started.

It turns out the national dialling prefix number is only one digit different (adjacent on a phone keypad) from a telephone exchange in Dawlish down on the south coast of England. There's a taxi company in Dawlish with the same 888111 for its telephone number.  We started to receive calls late at night from people wanting to order a taxi. Presumably they'd been to a pub, had too much to drink, and then needed a taxi to take themselves home. Rather easy to mis-dial in that level of mental capability.

Fortunately the facilities on the VOIP service allow us to redirect call straight to voice mail on a timed basis. We were able to say any incoming call between 10 p.m. and 7 a,m. should route to voice mail without disturbing the guests. 

The full number had also been previously allocated to a local business that had failed. We started to receive calls from a debt collection agency wanting contact the owner of the failed company. Thanks to the facilities on the VOIP management system I was able to contact the agency and ask them to remove the number from their database.

Edit: 28th Aug 2015 - We had a call from a different debt collection agency wanting to contact the previous owner of the number. They too have agreed not to call the number again. These calls are not a major problem, but I don't want the guests disturbed by them.