Ask for an appeal form and get to the CAB asap, reconsiderations are automatically done when you put in an appeal. Be very careful of phone calls from DWP & ask that they only contact you in writing.
While doing some Twitter campaigning for the Responsible Reform (Spartacus) Report I came across an email from the Benefits and Works website which contained the following members only information:
"Claimants employment and support allowance (ESA) and disability living allowance (DLA) appeals can now be withdrawn simply by a decision maker telling a tribunal clerk, without providing any evidence whatsoever, that the claimant told them on the telephone they no longer wished to carry on. The shock change to the principle that appeals can only be withdrawn by the claimant themselves, and only in writing, was introduced last month in a bid to reduce the growing backlog of appeals."
Someone from the Spartacus campaign has found another online version of it:
http://www.limbcare-parliament.org/ so you can read the full article there if you aren't a member of B&W.