Ian,
Way back when I started in this industry it was illegal for a sole trader or partnership to trade under a name other than your own, or the fullnames of the partners, unless it was registered with The Registrar Of Business Names.
The registrar would refuse to register a duplicate name.
This was an excellent scheme as not only did it prevent multiple, unrelated businesses trading as 'Wonderclean' but it made the individual trader traceable.
Unfortuneately this registry was disbanded in the late 80's and the situation is now far less cut-and-dried. However if you started trading as Chemdry they would undoubtably be able to put a stop to it ( and posibly recover damages) as they are registered as a limited company.
Shaun, The r within a circle means registered.
John.