The failure or refusal of any cottonseed sampled, duly licensed as such under the regulations in this subpart, to draw, prepare, identify, and to forward an official sample of every lot of cottonseed made available to him for the purpose, in accordance with these regulations, shall be cause for the suspension or revocation of his license. A sampler's license may also be suspended when the sampler (a) has ceased to perform services as a licensed cottonseed sampler, (b) has knowingly or carelessly sampled cottonseed improperly, (c) has violated or evaded any provision of the Act, these regulations, or the sampling methods prescribed by the Director, (d) has used his license or allowed it to be used for any fraudulent or improper purposes, or (e) has in any manner become incompetent or incapacitated to perform the duties of a licensed sampler.