How do I deactivate an account?

I have two accounts one under the email address of prune71472@yahoo.com and one under vicious81017@gmail.com. They are both attached to the phone number of 507-829-4295. I am trying to deactivate the prune71472@yahoo.com account as I no longer have that email account. I am trying to book a sitter for this weekend, but it won't let me because of my phone number is attached to both accounts. Please help me.