So you had one bad experience, Bill Plant vetted him and he was likely an ADI when he joined and if he is no longer registered, then he was struck off - it's in his agreement that he's obliged to tell BP if he's no longer an ADI the same way it's our obligation to tell our insurers if we get points on our licenses. This does not by any means make BP as a whole a "rip off". My first BP instructor sucked, my second was excellent and passed me first time with him (second time of me taking tests) in an unfamiliar area down roads I absolutely hated in our early days. He also passed my best friend's sister before me, and an ADI he trained now teaches aforementioned best friend. He brought 35 years experience to the table, the last one brought 10, but seemed uninterested in his job. Like all instructors, who you get is always going to be pot luck, driving schools are no different. This is why people generally prefer to have instructors referred to them through word of mouth than approach schools; because then you know what to expect.
Judging by your aggressive angry tone, I can only imagine what he had to put up with on the phone from you and if I had aggressive students, I'd refuse to teach them too. For both our sakes. He has the right to call the police if he feels he's being harassed. Bill Plant are a franchise, not an agent. If you're still this upset, inbox Bill Plant on facebook, you'll find they're very helpful if you construct a decent complaint instead of "muh instructor sucked". Without us being in the car with both of them, it's hard to take sides, on one hand maybe the instructor really was poor, on the other - your wife was still driving in circles in second because her clutch control and overall confidence were both bad, progress differs from person to person. We have another thread on here from someone who's been on roundabouts on their 6th lesson - by my 6th I still hadn't seen a roundabout and was still practicing the basics of turning left and right.