PROBLEM:

"A" promised to pay "B" in exchange for a check.
"A" gets the check.
"A" offers and "B" accepts full payment from "A" on the same day for said check.

"B" acts as though payment was not offered by and received from "A" and even continues to send "A" payment demands (bills). The damage to "A" is, obviously, the undischarged balance "B" still alleges is due

"A" can show / prove how, when and by what method legal payment was made by "A" and accepted by "B".

QUESTION:

Since "B" received payment from "A" and did NOT discharge the debt with it, what cause of action might "A" look to base a petition against "B" on?

BREACH OF CONTRACT?

Provided "A" can unequivocally prove "B" received and accepted payment, is "B" in breach of the contract with "A"?

Contractually, "B" did what it was supposed to do in a timely manner, which "A" concurs; "A" did what it was supposed to in a timely manner but "B" does NOT concur...and thus "B" is not fulfilling any obligations of a paid creditor.

NEGLIGENCE?

Once payment is (determined) made by "A", and since "B" has failed to take the actions one is obligated to take upon payment, is Negligence the more accurate cause of action?

In either cause, "A" must show / prove how and when payment was made to and received by "B" (which "A" can easily do); which cause is a better approach for the simplest win??

Or is it something else?

I hope this makes some kind of sense to someone out there who will take the time to consider this and respond.

I wish you all the BEST out there!

Jeff