made a new appli IHS payment refunded because of old case

[faisal1983]

i applied for a visa for my wife on june and got refused at the end of September because of the english language test and got the ihs refunded a few days later. we did the test again and reapplied on 20/10/2015
and paid for another ihs number with the new case but on November 18 i got an email from the ukvi saying the my old case has been refused and we gonna refund ur ihs money and the next day we got the ihs refunded.
i emailed them but the response was that its refunded for ur old case.
should i pay for a new ihs again and send them the number and letter or will they relaise they made the mistake and ask for the payment in due time?