Refused entry

I noticed I haven't received any email recently <br> Notifying me about my account . <br> <br> I approached my gym on 2015-06-1 and lady said <br> Only one month is due for R679.00 . I used my card and the amount was deleted from my account. <br> <br> Come Thursday they stop me from entering saying I must bring my bank statement to prove this ? I got the slip, debited amount via SMS . Why must o show my private account details to complete strangers VA? ? This doesn't sound right ? <br> <br> <br> <br> Tax invoice no. R 768 - *** <br> Member ***0