DSL

Hello, I have got an email on (24/8/2018) from info@o2.com about a DSL contract that I have applied for in October 2017 which didn't ever work and at this time when I went to O2 shop I was told that the contract was canceled by the company. Ofcourse I don't need the contract now but O2 already sent me an activation date on 5/9 and I'll not be in Germany before 7/9, what can I do to stop the contract? If it's not cancelled yet ,and to stop those emails.
Thank you