Tele2 even after all payments cuts our connection and then asks us to pay re-installation fee

We took Tele2 package on June2016. on 1July 2016 we paid 2times 20Euro by our ING bank account. where 10Euro was for installation and rest 30Euro for first 3months usage fee (10Euro each). But Tele2 claims they recieved only one payment. Even though they can see both the payments in their accounts (confirmed by the customer care on 2Nov2016 on phone).
Hence they considered the only 20Euro they have recieved as -10Euro installation and 10Euro for june2016. And then they withdrew10Euro from our ING account for July. Laterwe blocked them from self-withdrawal because they kept saying that they can't find other 20Euro. So Tele2 sent us an email that they are cutting the connection in Sept or we should pay them 10Euro for August. We did pay again 10Euro on 15Sept 2016. Then on 16Sept evening they cut our connection. On 26th Sept evening we got our connection back.
From September we have to pay 32Euro per month. We did pay the same for september and October.
But at the last week of October we get a mail from Tele2 claiming that we need to pay 60Euro since our connection was cut and it is reinstallation fee.

The connection they cut in September was not because of our fault.... we always made payments but if they can't see then it is not our mistake.
With our laptop, wewent to Tele2shop in Spui on September and their colleague Ms Mediya made a screen shot of my bank statement and attached it and wrote an email to the Head Office from my laptop only, that she can see everything is paid properly by the client on time then why are they facing problems. Yet Tele2 never replied us back.

We don't want to pay this 60Euro since it is not our fault.
We have attached our bank statement copy herewith.

Please suggest what should we do??