Rental payments

Hello,
we lived in a property in Brussels for almost 6 years and left there last summer when we did check-out with expert and everything and we had no problems at all checking out, and our deposit was returned. Everything was in order.
We are now living in temporary accommodation and most of our things are still in storage until we find a permanent place to live.
However, a few months after we left Belgium, the landlord contacted us to say we somewhere along the line had not paid two months rent, which we cannot believe since we had a standing order with the bank.
However our account in Belgium is now closed and all of our statements are still in the container so we cannot double-check there yet !!!
Can anyone advise me on what to do?
Just today I had a reminder from landlord saying he wants this money, but I am still in the same position and cannot check !!
Do I need to pay this and hope to get it back if he is correct?
Or may I have him wait until I am sure if this is correct or not?
Any suggestions please.....
Thankyou.

Order new statements I d be furious if I were your landlord and you had not paid and use the location of your bank statements as an excuse