I had a horribly stressing experience when trying to move my BB and telephone provider a couple of months ago.
I had changed to Virgin last year, (having been with the same provider for BB since 1996). Went to Virgin for two reasons, those who used it said how helpful they were AND they send an engineer to the house to set it up.
Yes, I have had no problems at all with them and it is easy to get through to helpline if needed. BUT they are expensive.
So, thinking I could save over £10 per month I found a company called John Lewis Broadband. I assumed (I beleive now wrongly) that they were part of the JL group, who are re-knowned for their good customer service.
The original call to them (I thought just asking, found me actually signing up with them) this was simple and a charming young man at the end of the phone. From then onwards it was a downward cycle.
I will not list the endless problems I had over the next 48 hours, but enough for me, finally, to decide to cancel that agreement (well within the 14 days legally allowed).
Then I had a great battle to get returned to me the money I had paid with the original phone call of a stet-up fee plus one months rental.
Only by finally sending a letter to their Complaints Department and getting my own Bank to take up the matter did I get this money returned to me after several weeks.
Staying with Virgin now, decided the extra cost is worth while not to have the stress.