Incorrect bank details resulting in me paying the arrears!!

I have been a loyal customer of Virgin active for many years and earlier this year i registered my 3 year old to join. The incorrect bank details were captured and my account automatically went into arrears. last week when i attended, i was told the contract is cancelled and i needed to pay R700. I contacted Nokulunga Gqozo who said i must pay or else i cannot rejoin.

Why must i pay the arrears when this was not a fault of mine?

Terrible service Virgin active!!!