Being billed for special numbers

Hi<br> <br> I suddenly got billed for phoning 0861 numbers while I still have any-time minutes available. Tried speaking to customer care got told they cant do anything till I was billed for the calls as they don't have access to my call log until an invoice was created.<br> <br> I would like to get this resolved before I get billed for the calls. I phoned ***on the 25/05/2015 the call was 17 minutes long and was subtracted from my minutes. Phoned the same number on 03/06/2015 and got billed for the number instead of being subtracted from my available minutes. I have phoned 0861 numbers many times in the past and have never been billed for them. Why am I suddenly being billed now?<br> <br> Please assist with this