Paid £2,600 when I passed my test last year. I was living at home and could pay it in one lump. My girlfriend recently passed hers and by this time we were living together. Phoned Co-Op to see how much it would be to add her to insurance. They wanted £500 for the year. We said that was reasonable (we're 18 and 17), but could we pay it in monthly installments. They said no. So we temporarily insured her for a week.
The following week we did the same. And so on and so forth. This was tons more expensive for us, but we could afford weekly payments. Tried to put her on the insurance again yesterday, only to be told we've exceeded the maximum amount of times that you can add someone. We asked how many was the maximum, the woman said '3'. Bearing in mind, we'd done this about 7 or 8 times, and no one has ever said anything of the sort to us on the phone, or in writing.
Phoned complaint line (an 0845 number, of course), was put on hold. Situation isn't resolved and they've said they'll get back to us, which they haven't. Terrible customer services. I will not be renewing with them. They have lost out on my £2,600 for next year.