Invisible account handed over.

I've been chasing this account up since January of this year without success. I've been on the phone three times tonight to ***, then referred to 082111 and referred back to ***, then told the accounts department are closed. Suddenly a final demand.<br> <br> I've phoned the customer care and enquired many times this year as to the account status and have been told there was no problem with the account. This account never appeared on my Vodacom portal, I have received bills and paid as before when the account was with Nashua Mobile. <br> <br> Having had the account missing, then untraceable whilst attempting to resolve it, and now it is deleted, I am disgusted that I have got a final demand suddenly. <br> <br> I've called countless times this year trying to trace the account down and always been told I am in good standing. Whilst I've put effort and time into resolving this I have now been threatened with legal action. I find this disgusting. A simple phone call to me could have cleared this problem up, rather than me chasing.<br> <br> I'm not happy at having to pay this account fully within the 21 days and would be happy to make an arrangment, except I'm told there's no issues when I call. Please explain.