Sorry - this is capitalism! Companies are free to do as they please - as long as they are not engaging in fraud; misrepresentation etc...
However, if I had taken out a loan or mortgage with A&L (most likely via a freephone 0800 sale number!!) and then they forced me to call a 0870 number to deal with them, one may have a case in law that this was some extra "hidden" charge that they had not told you about.
You could then ask them to cancel the contract at no penalty to you (ie: move your mortgage to another bank). If they insisted on charging you for this you could have a case at the small claims court (up to £5,000 I think) under the consumer credit act etc... You could also complain to the relevant body who regulates the consumer credit act.
You can apply for a county court judgment online; and the cost is low - around £35 or so I think; and the defendant cannot claim costs against you.
This would be fun to say the least - as A&L would really start to sit up and take notice if not only they were losing customer because of their 0870 rip-off number; but they were taken to court because they would not supply a geographical number.
As A&L are making money from their 0870 numbers it could well be argued that they are indeed making a hidden charge to you. The court case could be fun as they could be forced to reveal how much they are making; plus I'm sure they do not insist you call at 0870 number in their mortgage/loan documents. They could also be forced to disclose how long callers are kept in queues etc...
The court would have to feel that it's reasonable that A&L should provide the ability for you to manage your account via the phone - and not via email or post.
The real winner is if you are visually impaired! Then you might well have a claim under the disability discrimination act - as you cannot use email or mail and are forced to call a premium rate number.
Of course they might cave in and give a geographic number just for you and/or for the visually impaired. In which case that number might for some unknown reason find it's way to this site....
))