Rewrite the following sentences to make them concise.

$1.$ We should cease and desist at once all official company correspondence with the company that supplies our wholesale goods and services until we determine if it has complied with our official company policies and so forth.

$2.$ I have been attending classes in the field of business at the community college which is local and close to the building at here I am currently employed and my office therein.

$3.$ Derek stopped by at about $1$:$22$ p$.$m$.$ He wanted to discuss something. He was concerned about our merger with Addi$-$ son, Plymouth and Partners. He thought we should do the due diligence again. Derek started some of the work. He is a very responsible executive.