Thank you for your email and the information. We use an 0845 number for our e-commerce website because it is a memorable number and  because we believed it was giving a good deal to the customer, most of whom are not in our local area. We use an 0800 number for our gas central heating business. The only 0870 number referred to on the site is for a 24 hour breakdown line which is the insurance company that covers the central heating guarantees. Unfortunately this is not our telephone number but i will pass your info on.
I will pass your email onto our telecoms department and see if i can get the 0191 numbers for which the 0845 number refers.I presume that you do not have an objection to the use of an 0800 number as i think that this is free for the customer to call from a landline.