Planning permission and Building Regs for exisiting conservatory

[LSurrey]

I had a conservatory added to the back of my house in 2008 built by Anglian. The conservatory is 14Sq meters in area and the depth is 4m, width 3m. It is not higher than the existing first floor windows and the original sliding door/windows to the back of the house remain in tact so there is a physical barrier between the conservatory and main house. I was told at the time that planning and building regs were not required as it met with Permitted Development. There is an electrical power supply and lighting that comes from the main fuse board. There is also heating which although comes from the main house, it has an independent on/off and temperature control from the main heating system and the rads have thermostatic valves. I recently made enquiries about a new roof for the conservatory and was told by the sales rep that the conservatory was illegal and I had contravened planning and building regs. I am confused because under the area rule i.e. less than 30SqM I don't think I have broken any rules but it is 4M in depth on a semi detached house, which implies I have. I was also told that the power supply and the heating supply are illegal, but I think they may be allowed under the building regs. Incidently, he also claimed that if I changed the roof to an Ultraroof 380 then I would meet all the requirements he said were illegal and still not need to apply for planning or building regs, surely putting on a hard roof makes the conservatory no longer a'temporary structure' and would require some form of permission?