I stopped my DSL account with IDM last month, first I want to inform you that those people (IDM) stall like hell !!! they just want to buy time and call you everyday asking you "Why you want to stop ?" you answer them, then 2 days later they call you and ask you the same question "Why you want to stop ? do you to switch to iFLY ??", Once you make it clear for them they will send you this paper :
http://www.mediafire.com/?gvq3v8wlgnl4qaa
You print it, fill it, sign it, scan it and send it back to them to this email address
CCU@idm.net.lb (Customer care).
They will reply that your request has been submitted successfully but they wont send you the DESIRED paper the CANCELLATION paper before the first of the next month. Me I sent the email requesting the cancellation at the 20th of August they told me that they will send me the cancellation paper at the 1st of September.
Be careful !! they didnt send it to me the first of September they sent it the third of September, after calling them everyday 3-4 times and spamming them with emails and they kept replying to me with lame reasons like "the employee responsible of those cancellation paper is on vacation" or "this employee is in her lunch break right now please call later".
Last and not least they will send you this paper (3rd of September in my case) it will be a paper signed by IDM the ISP and GDS the DSP, once you have it send it to ogero asap because Ogero or any other ISP wont start reading your application if this paper is not present ;)