Finally saw the Watch Dog  report on Drive Dynamics. Starting about 2008, when Red were putting lots of instructors on the road, and everyone was cutting prices I stuck to my principles until we were desperate and I signed up for 6 months, £99 per week to D/D.
Had to have an online diary, (never came) so my wife came with me to speak to them. First thing they did was offer us coffee, it never came and the wife said, that's not good.
Everything is done by text, you give them post codes which they ignore and send you pupils a days drive away. You text back refusing that pupil then two weeks later get a text saying the pupil is complaining because you didn't turn up.
I paid weekly letting them use my debit card, sometime I paid twice in one week! Sometimes I got threatening texts saying I hadn't paid that week so would be charged extra.
You did the first lesson, then two weeks later you got the payment for that lesson.
Because of D/D I realised what a fantastic local bank I had, which also happened to be D/D bank.  Where I couldn't get to speak to anyone at D/D the bank could and was able to inform them they were looking at their account and could see they'd taken the money.
I gave the required notice to end the contract and guess what, the next week they still took the money. My bank got it refunded but they did the same the following week. With that the helpful young men at the bank took my debit card, cut it up and reported it lost. I got a threatening text the following week because they couldn't get a payment. In the six months I worked for them I got nine pupils, plus two they sent to me, which naturally I ignored, two weeks after I left. 
They may have a bad reputation with pupils, they have an even worse reputation with local instructors I've spoken to.