Upgrade

I have been with cellc for 8 years and i have never waited this long for my upgrade to be delivered all these days when i call them i am told it takes 3 to 7 working days for deliveries. On the 7th day when i call i am told that they that I are out of stock. Why wasnt i told that when i was upgrading. I find this unacceptable and dishonest. You guys cant even let me know when stock will be available. I upgraded on the 3rd of August and today is the 19th of August and still a big company like cellc doesnt know when stock will arrive. I have called you guys sent emails and even inboxed you guys on all your social media platforms and all your responses are lies. I will never recommend this company to anyone. Please advise on how to cancel my upgrade im not renewing my contract with you guys.