Dude, same thing happened to me.
I try to log in but it says invalid username or pass even though the log-in details are correct.
I'm able to request new passwords via email but even when i try logging in after changing the pass it will still say invalid user or pass every time.
Also in the email it will say "Hi Character Name Unavailable, We have received a request to reset the password for your RuneScape account."
If you bought membership on the account using a debt card and you go here to cancel membership instead of showing your char name it will say just say something like cancel membership for user #A332DFG"
https://securecard2.jagex.com/p=bcu9g*DbBJDB7H6LqG1ya8HsfouobXJredaFO4jciSg/cancelbycard.ws?value=AAAQUWvJJazi3O5RPCWA176ETA
what I don't understand is if they deleted our account why don't they notify us, and if we were banned it would say " account disabled please visit message center" but instead keeps saying invlid user pass when i try to log in.