Well, lauds considers you untrustworthy for selling your account and your account could have been used for malicious purposes after it is sold if the new owner isn't honest about his business. That is why he gave you the negative trust.

There is no way of removing your negative trust, unless Lauda decides to remove it themselves.

Do some good to the community, stay active. If you can prove that you're trustworthy again i think he'll be happy to remove it eventually.