Hello. I've gotten a letter for collection which it's over 14yrs old on phone bill which I don't remember but they got all my correct information. It was a large amount but they made a deal if I pay half and it would be paid off.

What should I do?

I said I want proof of the bill and I paid part of the half. Should I call my bank to not pay them? Or is it too late? Please help. Thank you in advance.

Well that old of bill, they can not sue you for it, so there is no legal reason to even pay them, unless you do something to re-affirm the debt.
Your best bet is to just ignore them completely, and esp, never ever talk to them on the phone, In fact most likely this is a fraud of some sort looking to get your personal information from them.

You sent them a payment?? Did you get any agreement not to pay the other half first ( in writing) you do know by paying them, you obligate yourself to pay the full debt if your agreement is not in writing,
Also did you send it before getting proof of debt, this may be just a fraud ?
What were you thinking??

Nerd, why would you have paid half of such an old bill without some kind of proof? I'm sure I've done dumber things as well. Telling your bank to not pay them - you have to go to the bank and fill out paperwork giving a good reason not to honor your check at this point of the game is not a good idea. (unless you have a dandy excuse you could give) I'm sorry to say this, but it looks like you made a very costly mistake.

Thank you so much for all the advices. I called the bank and had it dispute and stop payment.