Poor management of account result in huge bill

I entered into a spit billing contract between myself and my company with vodacom. My company sponsors an amount anything I exceed I pay the difference. The contract started the October 2014, they contact me this year July 2015 and inform me no debut orders until now was deducted and I must pay the outstanding amount. <br> <br> I can understand one or two months, but 10 months later and now you wake up. My contract clearly states if the amount exceeds the sponsored amount EACH MONTH you must notify my employer. This was not done. The contract also states stop the service is payments are not made. This is poor management of account on their behave and I don't agree that I should be kept liable for this and also my company.<br> <br> Also the contact details and postal address is not correct. Not the same as i submitted to them so invoices was send to wrong address, even the account holders name isn't mine