Incorrect deduction.

I’ve written a number of reviews on Sizwehosmed and none of them have been positive, this one won’t be either. After my last review which was about R1371 that I supposedly owed them I now apparently owe them R341. My contribution is deducted via a debit order and I check that it’s the correct amount and deducted every month . Can anyone advise how I owe them anything when they request the deductible amount and it’s paid every month. I got a call from them about two weeks ago and the woman told me the problem was resolved and my next deductive would only be R 341. I asked if that was all that would be deducted and she said yes. At no point (I asked more than once) and was assured that it was. She never said that it would be added to my normal amount. I received the sms today only to find that instead of deducting my R 3358.46 the R 341 had been added to it. I would dearly love someone who has any idea how this is possible to let me know. Surely if I paid what they requested I can’t owe them anything. I’ll never recommend them except to serious enemies. This has been an issue since July when they deducted 9015 , August it was R 6716.92 the same in September, they then said they had done an audit and I owed R1371 , I then did another review and was told they were going to do a recon on the audit and came up with the same amount, another review after which I got the call to say that this deduction would be R 341, I have the name of the lady who told me. The amount of R 3699.46 was never mentioned. To put it mildly there accounts department is absolutely useless. I’ve had 5 different amounts in 5 months and none correspond to my correct deduction.