Our 0345 number is hosted with a provider and calls are directed to our incoming line which is part of our hosted PBX system.
In case of problems you can dial directly to +44 203 856 1746.
(0345, 0845 and 0203 are all Geographical rate numbers)
Details on charges here : https://www.ofcom.org.uk/phones-telecoms-and-internet/advice-for-consumers/costs-and-billing/how-much-does-a-phone-call-really-cost
Don’t forget the support procedure to help speed things along.