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It would really depend on why you disputed it in the first place. Just disputing something to see if it will be removed is not a good idea. Give a little more information please.
SInce you have already disputed twice don't do it again. It is only hurting you.
I am going to assume a CA is listing the TL. If so, send them a DV letter.
Sorry. You might want to spend some time reading the links in my signature.
A DV is Debt Validation. It essentially puts the burden of proof on the collection agency to prove you own the debt.
PFD is a pay for delete. It is an agreement between yourself and the CA (collection agency) that if you pay the debt, they will remove it from your CR. This needs to be in writing on their letter head with a signature.