Discontinuing proceedings using N279

[SarahGilly]

I am trying to discontinue a claim against a defendant as they are agreeing to pay. We created an invoice for them to pay by Credit Card but then they asked to split the invoices so that could pay on two cards. We have done this and received one invoice payment that totals half of the amount to clear. If I use N279 do I need to ask the courts permission to discontinue as we have received a part payment. I have a short timescale to discontinue proceedings and wonder if this is another stalling tactic.