3 weeks and still no cancellation or collection

I upgrade via the online service, spoke to celeste, my phone was delivered promptly but I was not happy with the handset. Within 24 hours of receiving the handset I phoned and cancelled the upgrade. On the 22nd of January I got an sms to advise it had been booked for collection. Still the phone is sitting on my desk. A week ago I phoned to follow up, was put through to 3 different people and 3 different departments, none of which helped me, I was simply told the courier is having trouble.! So much for a 14 day cancellation period, considering its been more than 14 days they I have been promised that the phone would be collected, and going onto a month since the first telephonic conversation and upgrade!